


Vice Versa

by AvocadoLove



Series: Captain Stark/Iron Steve [1]
Category: Captain America (Movies), Iron Man (Movies), The Avengers (Marvel Movies), The Avengers (Marvel) - All Media Types
Genre: Alternate Universe - Role Reversal, Angst, Angst and Porn, Hurt Steve, M/M, Not Captain America: The Winter Soldier Compliant, Palladium Poisoning, Role Reversal, Tony Stark Has A Heart, Trust Issues
Language: English
Status: Completed
Published: 2014-04-04
Updated: 2014-06-21
Packaged: 2018-01-18 02:44:29
Rating: Mature
Warnings: Graphic Depictions Of Violence
Chapters: 4
Words: 21,857
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/1412047
Author URL: https://archiveofourown.org/users/AvocadoLove/pseuds/AvocadoLove
Summary: <blockquote class="userstuff">
              <p>During an alien invasion, Tony is transported to an alternate universe where Steve is Iron Man and he is Captain America. </p><p>Also, Captain Stark and CEO Steve Rogers are together on the sly. Awkward.</p>
            </blockquote>





	1. Chapter 1

**Author's Note:**

> Be aware this is the first of two stories. This the first, told from Iron Man Tony's POV. The second story, told from Captain Stark's POV, will be posted shortly and will probably be called 'Versa Vice'.  
> ****
> 
>  
> 
> If you're having trouble visualizing built Captain Stark, maybe this will help. (You're welcome.)  
> 
> 
> Finally, there are three other codas set in the same series. They are this universe's origin stories for Captain Stark and Iron Steve, and a sex scene. It's not necessary to read them to understand this fic.

 

 

* * *

 

 

"Does this count as the forth alien invasion, or the fifth?" Tony wondered as he barrel rolled to avoid an alien fist the size of a Volkswagen Beetle. The alien in question had hard, pebbly yellow-gray skin, which so far was immune to bullets and repulser blasts. It was also huge. Not Empire state building, huge. More like Trump Tower. Oddly the same color of skin, too.

"Forth," Clint replied over the comms.

"Fifth invasion," Natasha's voice was cool. "We have two types of aliens here, so two separate invasions."

Tony glanced down to street-level just in time to see her dispatch one of the second species, which were gray, small, and human-size except for beaky mouths and honest-to-god bat-like wings. Those aliens, at least, were killable. Too bad there were hundreds of them swarming in every direction.

The big and ugly rock-alien roared at Tony, clapping two hands together and nearly catching Tony between them. Then it roared again as two dozen bat-aliens swarmed up its legs, stabbing with red-tinged spears.

Tony could almost thank the bats, except they'd proved far too happy to kill any humans who got in the way, too.

There had been no warning, no indication where either race had come from -- no declaration of war. Or "Hiya, you don't mind if we use one of your most populated cities as our personal battle ground, do you? Kay, thanks." The rocks and bats only seemed interested in fighting each other.

"I've decided," Tony said as he hovered to fire a repulser at a couple of bat-aliens who were scurrying up the side of a nearby building. Whatever they used their wings for, it wasn't for flying. "I'm not counting this as an invasion. It's like they don't notice us at all. In fact, I'm insulted. We're Avengers. We're _the human race_ , excepting Thor. It's kinda hard to miss us."

Steve's voice broke in, tense. "Cut the chatter, everyone. Thor, any luck getting through to either side with All Speak?"

"None, Shield Brother," Thor boomed. And really, Tony could have figured that out for himself. The clouds overhead had taken an ominous, steel color as the God of Thunder became frustrated.

Tony circled around the biggest of the rock aliens again, though he couldn't shake the feeling he was about as effective -- and as annoying -- as a housefly.

"And why did they take their grudge match to China Town?" Tony groused, ignoring Steve's command. "I _like_ China Town. Why don't aliens ever invade Yonkers? Or Milwaukie?"

He heard a small click in his ear as Steve switched to the private line between them. "How are Yonkers or Milwaukee even remotely related?"

Tony grinned. _Cut the chatter, Captain hypocrite._ But he wasn't complaining.

One of the bat-aliens made a long leap from the building to the giant rock alien, a spear clutched in its hand--claws?-- and left a two foot gash on the pebbly skin before it was shaken off. Hovering in place, Tony targeted the gash with a repulser blast. The rock alien swung around, tiny eyes red with rage. Well, that got its attention.

"Easy," Tony replied as he dodged a swipe. "Yonkers and Milwaukee don't have one good Mexican food place between them."

Steve grunted, "And China Town does?"

"Surprisingly, yes."

Below, Tony caught a flash of Steve using the shield to bounce off the ankle of one rock alien and bowl headlong into a group of bats. There were a lot of high-pitched, batty screams, and a few moments later Steve was the only one standing among a pile of aliens.

He got an idea. "Cap, get me one of those spears the bats were carrying."

Steve hefted one and glanced up to spot Tony. "Go long!" he yelled. Apparently he'd learned a thing or two from the Avengers' bi-weekly flag football games in the park. (The winner usually was whoever had Natasha on their team. Avengers flag football didn't mean no-touch-no-tackle football.)

Even three hundred feet above, Tony had to move quick to catch the spear as it flashed past. "Good arm, Cap."

"Think so?" Steve asked, then paused to take out another bat. "So why don't you ever want me on your side in football?"

Because then Tony wouldn't have the chance to tackle him sans armor, or visa-versa. But despite what Pepper claimed he did have sense enough not to say everything that came into his head.

Hefting the spear, Tony directed Jarvis to increase the power to his left arm. He aimed and threw, and it slammed into the shoulder of a rock alien and dug in at least a foot deep.

The thing roared with enough power to rattle Tony's eardrums.

"Well would you look at that." Tony switched the communicator back to the general channel to reach the rest of the team. "Those bat-spears penetrate the big guy's rock-skin. Scales? Hide? Whatever it is."

"Hawkeye, see if you can get a hold of some of those," Steve ordered, all Captain America again.

Tony could practically hear the grin in Clint's voice as he replied, "Got it, Captain. I'll see if I can put 'em somewhere sensitive."

Tony opened his mouth to add his (dirty) part when suddenly the HUD proximity sensors screamed at him. He fired his thrusters, banking a sharp left, but it was too late. The flat of a rock creature's hand seemed to come out of nowhere to slap him casually, horribly, to the side.

"Sir, brace for impact," Jarvis said.

As Tony tumbled through the air, he caught a flash of the side of a brick building. Someone had painted a mural on the wall -- an urban scene of neighbors coming together to plant a lush community garden. Well, it was about to get an Iron Man sized hole. He crossed his arms over his face.

But the impact didn't come.

The emergency stabilizers kicked in, and Tony opened his eyes, finding himself on the other side of the wall. No wait, he was on the same side -- the mural was still whole. He hovered in air and looked down at his armor, checking for damage. There was none.

Had he hit the wall and not known it? Concussions were freaky that way. The wall was completely intact, save for an odd shimmering on the surface. Had he... phased through the wall? And come out the same side?

A rock alien gave another roar, but Tony was out of arm's reach, and frankly he was too rattled to care.

"Jarvis? What just happened?"

"Unknown, sir. Working." Then Jarvis' voice sharpened. "Sir, I've detected an incoming object at your three o'clock."

Tony glanced up to see that a third type of alien had joined the fray from above, heading straight toward him. This one was metallic -- human shaped.

It came closer into view, and Tony's breath caught. No, it wasn't an alien: It was an armor very much like Iron Man, but painted charcoal gray with muted yellow highlights. It didn't look as heavily armored, as if the engineer had sacrificed protection for a lighter construct. The helmet was a little larger, too, with no mouth slit and wider, oval eyes which gave it a menacing inhuman look.

"Great," Tony grumbled as the other armor buzzed by. "Cap, we have a third party in. Someone's ripped off the Iron Man -- badly."

"I thought you said everyone was at least ten years out from your tech, Stark," Clint said. Trust him to rub it in, though he was right.

Tony lifted to intercept, and the other armor swung wide. It had extra repulsers on its elbows and knees, allowing it to arc gracefully through the air.

Okay, so maaaaybe the other armor wasn't that bad of a rip-off. Tony took quick aim and fired at it anyway. He was too mature for spite -- that shot had been for science. Just to test how the pilot responded. Really.

The other armor twisted as the pulse impacted, leaving a smoking dent. It returned fire with a thin laser beam attached to its wrist. Only Jarvis' quick reactions allowed Tony to dodge in time. The beam still scorched a small hole in one of the chest plates.

It was _on_.

"You're right," he told Clint. "I guess I just have to take this guy down and find out how they did it."

"Keep your eye on the ball," Cap warned. "These aliens need to be contained."

Tony ignored him. Besides... this new armor might just be connected to the invasion(s).

The other armor fired again, but Tony dropped and deployed a small, targeted missile he kept in reserve. While the other armor released what looked like a load of chaff to deflect, Tony flew by and strafed it with two quick repulser blasts. But the armor dodged with uncanny grace.

The other armor fired back, and it was Tony's turn to dart out of the way.

Then they were flying, weaving, ducking, and chasing each other through the air. Firing and counter-attacking in a high-tech dogfight.

"Jarvis, hack in and shut that suit down. I want to _own_ them." Tony was going to pin the pilot of that armor to the wall, pry him or her out of the suit, and find out where they got the specs for the Iron Man, because no one was even _close_ to this level of tech. Then _maybe_ he'd let Shield get a crack at them.

But try as he might, the other armor was hard to get a bead on. They twisted through the air, shooting at one another between flailing rock-alien arms and screaming bat aliens.

Tony had to admit, grudgingly, whoever was in there was good. The other suit wasn't as fast as Tony's, or as heavily armored, but the extra repulsers on the joints gave it more maneuverability. And those laser weapons were a bitch to avoid. Tony had three more smoking holes and one of the flaps on his left arm was completely immobilized.

"Sir, there is a virus attempting to hack into my systems. I am readying antivirus protocols, but it appears to be a mutating encryption."

Tony scowled and came low to shoot at the other armor again. He grazed it's leg, though he didn't see any damage aside from a little smoke. "Any danger?"

"Not so far, but it is rather complicating my own efforts."

"I want an airtight firewall between this suit and the home servers." Tony switched directions to lose the other armor for a moment.. He hovered and looked down at the ever-widening battlefield. The other Avengers were containing the aliens -- barely. He had to figure out a way to end this and rejoin the fight.

It took a moment, but then he saw a familiar flash of a red, white, and blue as Cap's shield whizzed through the air to strike at the shin of one of the rock aliens. It didn't do much, maybe dented the pebbled skin a little. The shield bounced back, and ricocheted off two of the bats before returning to Steve's hand.

Jarvis pinged a proximity alarm. The other suit was on his tail again.

Tony opened the comm line. "Coming in fast, Cap. I'm drawing the other armor your way."

"Where?" Steve demanded. "Iron Man, I don't see you!"

He deliberately slowed, teasing the other armor with the possibility of catching up.

"What are you blind? Look up!" Tony landed in a crouch, and the other armor, like an idiot, did too, right next to Steve. Tony raised his palms, gearing up for a twin blast, but hesitated as the other armor stumbled in place as if the pilot inside suddenly had trouble holding themselves up.

Cap turned and let the shield fly -- and it was so fast that even Jarvis' automated defense didn't have time to react -- because it hit Tony square in the chest with an unmusical clang, throwing him at least ten feet.

He landed flat on his back with Steve yelling in his ear, "I don't have a visual. Repeat, Iron Man, I do not have a visual. Where are you?"

"Ow," Tony groaned, and painfully stood, making a T out of his hands. He flipped up his faceplate. "Wait, hold on. Time out. Why did you--"

Then he looked at Cap, _really_ looked at him, and the air left his lungs like he'd been punched.

Captain America stared at him, but it wasn't Steve's face under the cowl. It was like Tony was looking in a mirror -- a younger, six-foot three mirror, with a thicker goatee and without any sprinkling of white hairs.

"Um. The fuck?" Tony asked.

At the same time the other captain took a startled step back and said, "What the devil?" glancing over at the second armor.

The second armor didn't raise his faceplate so much as the metal sort of pixilated away from his face. And there was Steve; fringes of blond hair plastered to his forehead with sweat. His face was gaunter, the cheekbones more prominent, and he was pale with shock. But it was Steve. In an approximation of Tony's armor.

"What the hell?" Not!Steve asked, looking between Tony and... the other Tony.

Captain -- Tony's Captain -- was still yelling over the comm for Tony to report, but for one of the very few times in his life, he was at a loss for words.

He turned to look up at the building with the mural. It was still intact, though he knew he had gone right through it. The slanting late afternoon light showed a distinct shimmering along the surface. "Either I had a sudden psychotic break when I busted through that wall, or--"

"It's an Einstein-Rosen bridge?" Not!Steve finished. "I saw you come through."

Okay, that was _so_ weird hearing that coming from his mouth. "Must be." An alternate universe was much more palatable than Tony going suddenly insane. Better for the ego, too.

He and the other Steve exchanged a look. Then Tony snapped his face-plate down, Steve's sort of flowed over him again, and they both fired their jet-boots. Not!Tony yelled something, but his voice was drowned as both armors shot into the sky.

Through the earpiece, Tony got a burst of sudden chatter. His Cap yelling for everyone to stand clear. The Hulk was on scene, and one of the rock aliens was falling onto a building. "It's coming down. Get clear, Hawkeye! Tony, where are you?"

He had a bad feeling which building was collapsing. "Shit! Hold on, Cap! I'm coming!" He aimed right for the wall, hoping the doorway worked on both sides.

The shimmer over the mural, barely visible, flickered in and out.

Steve's voice fell into static.

"No, wait!" Tony yelled and poured on the speed. In his mind's eye, he saw a rock alien crash backwards under the fury of the Hulk, saw the mural wall crack and crumble down...

The shimmer blinked out when he was three feet away.

Tony hit the brick wall hard, blasting through and tumbling into the building, taking out a few rows of cubicals before he came to a stop.

"Ow." Tony rolled to his hands and knees, his armor shedding brick and plaster off his shoulders and back.

The team had gone silent in his ear.

"Cap!" he yelled.

No answer. Tony toggled their private communicator line. "Steve?"

Nothing.

"Jarvis, did I make it through--"

But his question was answered as Not!Steve's armor landed daintily on the ledge of a nearby open window. "Are you alright?" Not!Steve's voice was deeper through his Iron Man suit, with the same flat reverberation Tony used.

It was an effort to stand, though Tony didn't need Jarvis' scans to tell him nothing was broken. His suit had taken a beating, though it could fly. He turned to Steve--no, Rogers. "Of course I'm not okay. You're in my suit!" Tony pointed at the other armor's chest. The arc reactor glowed red, not blue. "Wait. Is your name even Steve? Because you don't look like a Tony."

The other armor brushed his hand away. "I'm Steve," he said. "Steve Rogers, CEO of Rogers Incorporated." He inclined his head back at the action outside. "The big guy down there is Tony Stark."

"Good," Tony snapped. "Because that would have been ridiculous."

Rogers didn't reply. He hadn't opened his visor, but neither did Tony. It was too... weird to look at his friend's face inside his armor. An armor.

Only then did Tony realize there was a distinct lack of destructive noises. He moved past Rogers to look out the hole he'd made in the wall. Then he grunted. "Well, that's the second least expected thing I've seen today."

The aliens -- rock and batty -- had all frozen where they stood, as if they'd been hit with one of Professor X's mind freezes. (Huh. What if in this universe Magneto was Professor X, and -- No, he couldn't go there. Too weird.) One of the giant rock aliens had even frozen with one leg lifted to stomp on five bats, all cowering in the shadow of a taloned foot.

"I suppose you didn't bring those things along with you," Rogers asked. He sounded put out. "Or Milwaukee?"

Tony turned to him. Shock tingling up his spine. "Milwaukee?" Hadn't he and his Steve just been joking about there?

"The first invasion last week." Rogers's helmet turned to look straight at Tony, as if to read his expression.

Huh. Coincidence? "Nope. It's the first time we've seen these guys. They were attacking my dimension, too. Pretty sure I fell into a doorway they made."

Rogers nodded. "They attacked for about three hours last week, then stopped just like this without any explanation. Even Thor had never heard of them before -- He went off to Asgard a few days ago to ask around." He cocked his head as if listening to something Tony couldn't hear. "Cap wants to see you."

Tony literally had to bite his lip to keep from snapping at him. He followed his Steve's orders when he was good and ready, so why did this Captain think he could deal them out? But it wasn't like he had anywhere to fly off, too. "Fine," he said sullenly. "Lead the way."

 

 

* * *

 

O O O O

* * *

 

Clint and Natasha were standing with this universe's Captain America (he could not think of him as Tony -- Just Stark would have to do.). Tony felt the weight of their scrutiny as he and Not!Steve came in to land.

"You two are normal, right?" Tony asked plaintively, lifting his faceplate and turning to Natasha and Clint. "Nat, don't tell me you're doing the Katniss thing."

She raised a very fine eyebrow. "I was about to ask if we were sure that's really Stark under there, but you even sound very much like him."

Clint just stared at Tony, blinked once, then broke out into loud laughter.

Stark glared at Tony. It had been twenty years since Tony had seen that frown -- it looked like the one Howard used to give him when he'd destroyed something in the lab, and it put Tony's hackles up.

Stark wore a very similar Captain America outfit to Steve's -- the cowl had been tugged off his head and lay like a hoodie on his shoulders. His dark hair was the same shade as Tony's, but cut at least an inch shorter. 1940's ol' boy short. He didn't comb it like Steve did, off to the side, but neat and held back with pomade.

"Who exactly are you?" Stark demanded, the shield held tightly to his side.

Tony didn't bother with an answer. It was obvious, wasn't it? He was Tony Fucking Stark. One of many, apparently.

"How does this even work?" Tony asked instead, looking Captain Stark up and down. He even filled out the uniform the same way Steve did, what the hell. "Did Dad put you into Project Rebirth?" Tony's stomach dropped. "That son of a bitch. He tested on his own son, didn't he?"

"Howard couldn't find his ass with a map and a compass," Stark said, and Tony himself only used that flippant tone when he was trying hard to pretend he didn't give a shit. Weird to have it directed at himself. "Answer the question, Shellhead."

_Shellhead?_

"I'm Tony Stark." His smile was all teeth. "I'm Iron Man." He saw Not!Steve -- Rogers -- grimace at that. Tony turned and gestured to the building. "Got thrown through a wall by one of the big guys, and ended up here -- the multi-verse theory is officially proven, yay. I'll collect my Nobel when I get home."

"I saw him phase through that mural up there," Rogers said for Clint and Natasha's benefit. He looked at Tony. "Why weren't you able to go back the way you came?"

"The Hulk," Tony said. "Our teams comm units must function on different frequencies. I heard him take out Rocky over there, and I think they smashed the portal on the other side. Speaking of, where's Banner?"

"Who in tarnation is Banner?" Stark demanded, then turned to Rogers. "How do we know this guy isn't some screwball? Or... a clone? Like in the Clone Wars?"

"Ugh." Tony pinched the bridge of his nose. "You guys showed him the prequels? What, do you hate him? No, strike that. He's me. Of course--but come _on_. We knew enough to keep that away from Steve."

"Because where you're from... Steve is Captain America?" Clint said slowly, as if testing out the idea and finding it too weird to comprehend. Tony knew the feeling.

Natasha just stared at him like he was a bug she was considering squishing.

"We... haven't exactly found the point of entry for the aliens," Rogers answered Stark. "And technically, a similar but different dimension does fit into the quantum multi-verse theory, but..." He glanced almost in apology at Tony.

Tony shrugged and finished for him. "It's kind of unlikely. Changes on a quantum level are more of a random cascade, less of a 'Hey, let's have these two trade places,' deal."

Stark glanced between them, and no way did Tony ever wear that vaguely constipated look on his face. No way. "What does this have to do with the aliens?"

"The aliens did freeze when Mini-Stark punched through the wall," Clint commented.

"Okay, one: Mini-Stark is not going to be said ever again. I'm establishing veto power," Tony said. "Two, we were getting attacked by these guys in my dimension too."

Now the Captain smirked. "How about Stark Junior? You were born, what, in the _seventies_?" And Tony didn't know how he did it, but Stark made the decade of disco still sound far off and fantastical.

And technically, he was born in sixty-nine, but Tony wasn't about to share that.

Just then, a man in a red and blue spandex suit landed lightly on the concrete. "Hey guys," he said. "What did I miss?"

"Who are you?" Tony demanded.

"Spiderman." He cocked his head. "Who are you? Tony's older, tiny brother?"

Tony threw his hands in the air. "I hate this dimension."

"Speaking of irritating people." Clint was doing that weird thing where he looked like he was staring off into space, but was actually seeing something no normal human eye should. "We've got company. Media, ten o'clock."

Roger's faceplate immediately flowed over his face again.

Captain Stark sighed. "I got 'em. Iron Man, you'd better skedaddle back to headquarters. Take my weird double with you."

Tony didn't need to be told anything by himself of all people. He flipped down the mask, fired the thrusters, gained altitude and showed Rogers his heels, just because his suit was faster and he _could_. Only when he gained a few hundred feet did he look around and notice there was a very important gap in the skyline.

Where was Stark tower? Shit, of _course_ there wasn't a Stark Tower. Hadn't his Steve called it ugly at first?

Rogers suit came up next to him. Now that the aliens weren't busy destroying China Town, he heard the other suit's repulsers as a low purr, different from the high torque whine of Tony's suit. Rogers was running the cycles fairly low. It would make him short on speed, but enable him to conserve power.

"This way," Steve said, and headed off to the east.

 

 

* * *

 

O O O O

* * *

 

'Headquarters' turned out to be a large mansion on fifth street, edging a large green-space not too far away from Central park. There were no signs that said it belonged to the Avengers.

Rogers landed on a wide veranda, and Tony did the same. He flipped up the faceplate, and was surprised when Rogers reached over and slammed it back down.

"Not out here -- the paparazzi camp out just across the street."

"So?" Tony almost flipped it up again out of spite. This wasn't his dimension. What did he care if the press thought there was another Iron Man suit flying around? "Tell them it's a War Machine prototype."

Rogers had been heading to a doorway which automatically opened at his arrival. He stopped and turned. "What?"

"Iron Patriot?" Tony tried, hoping it hadn't come to that here.

" _What_?"

Oh. Rhodey had been assigned as liaison to Stark Industries to keep Tony in line. Which was why the first few years had been gleefully spent trying to drag the man in as much dirt along with him as possible. But of course Steve Rogers wouldn't need a military handler. He probably didn't know Rhodey at all.

"Never mind," he said and followed Rogers in through the opening doorways. The glass behind them closed and went opaque, leaving the room in a half-light. Only then did Steve reopen his own faceplate.

Tony was hit with a burst of realization. "So the world doesn't know you're Iron Man here?"

Steve gave him a startled look. "They do in yours?" Apparently the answer was on Tony's face because he asked, "Geez. How bad was the stock dip?"

"I think a few of my investors would have thrown themselves off my building, except they were too busy trying--and failing--to oust me."

The smile Rogers gave had a little more bite than the smile he usually saw on Steve. "Shield told the world Iron Man was my bodyguard. It's easier that way." He moved to a side table and picked up a waiting inhaler. He took two puffs off it as his suit seemed to break down around him, compacting down into dozens of pieces a lot like Tony's suitcase suit.

Tony gave the signal to open his own armor. He stepped out and it reformed, standing to attention. While Rogers was busy removing the last pieces from his arms, Tony casually slipped a communication bracelet around his wrist. In case of emergency all he needed to do was say the word 'Pineapple' and the suit would come find him within a radius of ten miles.

Finally free of the armors, the two men stared at each other. Tony was pleased he still had a couple inches on Steve, and at least twenty pounds of muscle. Steve was built like a jockey, small and slight. Some color had come back to his cheeks, courtesy of the inhaler, though the black flying suit he wore made him look washed out. His blue eyes were dull with chronic exhaustion -- a look Tony had seen in the mirror quite a few times himself -- and there were crows feet forming at the corners.

Steve stared openly back at Tony, clearly making his own assessments. "So... this is what you looked like before the serum?" Steve asked.

"You mean, Bizzaro Tony?"

"You _are_ Bizzaro Tony."

"I'll give you that, in this universe. And, probably? This is a new addition." Tony tapped his arc reactor, which glowed blue under his Metallica S&M 1999 tour t-shirt. He didn't bother with flight suits. Jeans and tight band shirts were more his style. "You have an arc reactor?"

Steve winced and pulled down the neck of his bodysuit, exposing the edge of a flesh-colored cap. "You don't cover yours?"

That had never occurred to him once. "What can I say? I like night lights."

Rogers shook his head and favored Tony with another long look. "It's hard to believe I'm not Iron Man where you come from."

"Well, you have to admit, you being Cap makes more sense."

"Not really," Rogers said. "You--uh, _he_ doesn't even like to use the coffee maker. He boils it by hand."

Tony raised an eyebrow. "You can do that?"

"Sure, if you practically like to chew your coffee." Rogers shuddered, then laid the flat of his hand against a glass screen. It lit, evidently recognizing his bio-signature, as did the rest of the room. The workshop was expansive, but more utilitarian than Tony's sleek design. Though a few tasteful pieces of art decorated the walls. Tony didn't see any sign of Dummy, You, or Butterfingers either. Not a smashed smoothie machine in sight.

"Good Afternoon, Mr. Rogers," a feminine voice piped in from the walls.

Tony barked a laugh. "Rogers, you kinky bastard."

"What?"

"You made your AI a female? An attractive sounding one?"

He knew that scowl. Universal to all Steve Rogers' in any universe. "I let Jocasta decide for herself. This was the voice she preferred."

Hmm. That was something Tony never considered for Jarvis.

"I am quite happy with my voice and gender identity, thank you sir," Jarvis put in helpfully from Tony's Iron Man suit, causing Rogers to startle.

Tony grinned and gestured expansively to the suit. "Jarvis, buddy, meet... Jocasta? That's eerily similar, but okay."

"Hello Jocasta," Jarvis said. "I am impressed by the encryption you used attempt to bypass my firewalls."

"Thank you, Jarvis. You put up a masterful defensive strategy."

"Stop. Weirdest blind date ever," Tony said.

And there was that true Steve Rogers grin. Not so 'aw shucks' as the one Tony was used to seeing, but simple and happy. Handsome, even in a thinner face. The one that always got his heart pumping.

Rogers beckoned Tony forward. "I got a few scans of the portal's event horizon before and after you came through. If you can plug, uh, Jarvis in, we can compare today's results against the Milwaukee invasion."

"Steve," Tony said, letting himself take in for a moment the similar but different workspace and the truly, _truly_ weird day he's had so far. "Let it be said, I like the way your brain works."


	2. Chapter 2

**Summary for the Chapter:**

> Woo, this chapter got long, but there was a lot I had to get in to set up the rest of the plot.
> 
> I'm taking a different direction with the Winter Soldier story line, so there are no direct spoilers for the plot of Cap 2, BUT there's a big ol' spoiler for the actual identity of the Winter Soldier. (If you've gone this far without getting spoiled on it I tip my hat to you.)
> 
> And finally, my apologies in advance to Nirvana fans.

 

 

Strangely, working with Rogers wasn't too different from working with Bruce. Rogers had a solid foundation in sciences, and quick intelligence to match. Not that Steve in Tony's universe was in anyway slow -- he constantly beat Tony in chess, which was obscene because chess was Tony's game. Steve had even won the first time Tony showed him 3D Sky Chess.

Using the readings from the two Iron Man suits, Tony and Rogers started to construct a theoretical model of the portal. As they worked, other subtler differences came to life. Rogers was a little more subdued, a little more controlled of an engineer than Tony. His tests on the available data had stricter parameters than Tony's, who enjoyed leaping ahead and seeing the results.

This universes' Steve Rogers didn't think in tactics -- he thought like an engineer. A time or two he even jumped ahead of Tony -- Tony had his moments, too, where he came to a conclusion before Rogers, but Rogers was always quick to pick up the thread again.

Judging by the way Rogers glanced at Tony in odd moments, he was cataloging differences too. Comparing Tony to Captain Stark.

"Okay, so tell me," Tony said, removing a light pen from between his teeth. He'd been taking notes on the holoscreen and chewing on the top as Rogers' AI spat out results. "Rogers Incorporated? You went with an incorporation?"

"You didn't?"

Tony shrugged. "Stark Industries. Technically still an LLC, but the name has more pizzazz."

"Huh." Rogers leaned back in his chair. One of his hands dipped into the pocket of a lightweight hoodie he'd changed into a couple hours ago (it did nothing to conceal how thin he was, but Tony suspected the hoodie was like his band shirts, comfortable as well as comforting). "It started as a college project. I wanted to work IT at MIT, but I couldn't legally be hired because I was so young. I could work as a contractor, though, if I was already under a company." He shrugged a thin shoulder and removed the rescue inhaler out of his pocket, shaking it a few times. "So I created R.I., the incorporated in name only. Then, when my first patent went through, I made it an LLC."

"Surprisingly sneaky."

Rogers shrugged again. "It was a useful loophole. Then things just..." he looked around, his eyes unfocusing, "grew. My patents for weapon process improvements started to take off." He took a hit from the inhaler, idly, almost as if he had to use it so often, he was barely aware of it.

But Tony took note of the dark liquid sloshing visibly through the containment well of the inhaler. He leaned casually back in his chair, stretching tight shoulders. "Stark Industries was filling military contracts from just before WW2. Good ol' dad," he said, irony thick in his voice.

Rogers turned serious blue eyes on him. "And now?"

"Clean energy." Something inside Tony unclenched as Rogers gave a nod of agreement. His company had gone green, too. "Along with other technological improvements. We no longer build weapons, but Stark phones are making a killing."

"Phones?" Rogers repeated, a blond eyebrow raised. "Really?"

"Manufactured with seventy percent recycled products, and the rest is almost entirely reusable after disposal. And made in the USA. Cap likes that." Tony grinned. "But half the fun's watching Apple and Samsung try to catch up. Here." He dug his own forth generation phone out of his pocket and flipped it to Rogers. "Take a look. We'll compare notes later. I want to know how you got the cool flowy effect over your Iron Man facemask."

"Smart plastics," Rogers said. "I'm trying to develop medical uses for it, in all my spare time." He bit his lip and glanced down at the phone's screen, but he wasn't really looking at it.

"In Afghanistan," Rogers began, and Tony tensed. "Were you... did Colonel Carter...?" Rogers looked up and there was a flinty hardness in his blue eyes. Something his Steve didn't have. "Did you get Peggy killed, too?"

Peggy? Oh. _Oh_. Peggy Carter.

Tony shook his head, and he wasn't sure what the expression was on Rogers' face. Somewhere between relief and self-recrimination. "Just a Humvee's worth of good men and women. Peggy was Steve's... I don't know what they were, but they were _something_ back in the day. She worked for MI6 and helped establish Shield."

"Oh." Rogers said quietly, then nodded. "Good. That's... I'm sorry about the others, but glad Peggy didn't... there."

Tony had a pretty good guess what must have happened. If Rhodey had ridden in the 'Funvee' with him, he would have died with Airman Myspace and the others.

Their awkward silence was broken as Jocasta announced sweetly that Captain Stark and Agent Coulson were requesting access to the lab.

Rogers' expression was more than a little relived. "Let them in."

Coulson looked indistinguishable from his counterpart in Tony's universe, but Stark had changed out of his uniform and into a flannel button down shirt and worn jeans. At least he wasn't swinging pressed slacks, but he had tucked in the shirt, and his jeans came up an inch off his ankles to show the top of workmen boots. Honestly, Tony wasn't sure which was worse. Steve sort of pulled off the preppy old man look. Why was Stark going with longshoreman old man?

"Stark," Tony greeted, pulling up a few holoscreens as if he wasn't completely aware he was the center of their attention. He glanced at Coulson. "Agent. You don't look surprised to see me."

"Mr. Stark," Coulson said mildly, not really answering. "Or do you prefer doctor?"

Tony's eyebrows rose. He turned to Rogers, who was frowning at the magnetic flux specs around the portal's event horizon. "You make them call you doctor? Wait, how many doctorates do you have?"

Rogers shook his head. "I dropped out of college when R.I. took off."

"It was an educated guess based on your personality type," Coulson said with a small smile.

"I so out-doctor you," Tony told Rogers, amused. Then, "Hey!" as his screen went temporarily black.

"Oops," Rogers said innocently.

"Nope. Don't believe that face. That's the troll face Steve uses when he 'accidentally' puts tinfoil in the microwave when he thinks I've been in the lab too long."

Rogers blinked, then craned his head around to send a narrow-eyed look at Stark.

Captain Stark didn't have a troll face. His was a shit-eating grin. "Your fancy heating machines are so gosh confusing." But there was tightness lurking behind Stark's eyes. Maybe Tony wouldn't have noticed it on another person -- he wasn't the most observant when it came to, you know, other people's feelings -- but he'd seen signs of stress plenty of times in the mirror.

Tony opened his mouth to ask, but Rogers beat him to it. "Tony, what's wrong?"

Stark glanced at Coulson of all people, then let out a long breath and ran a hand down his face. All the amusement was gone. "We just got the word in -- the aliens we were holding from the first invasion in the offsite lab reanimated when the second invasion started."

Rogers face drained of color. "Why wasn't I told this earlier?"

"One of the first buildings taken out housed the communications grid," Coulson said. "They weren't able to call for help."

Tony grimaced.

But Rogers had gone paper white. "How many casualties?"

Two long strides and Captain Stark was at Roger's side. "This ain't your fault, Steve."

"The hell it isn't," Rogers rasped. "It was my idea to move them to an offsite lab, instead of--" He closed his eyes and shuddered. "I should have just let you dump them in the Atlantic."

Stark murmured something Tony couldn't catch. One large hand rubbed between Roger's shoulder blades. It looked like a familiar gesture -- apparently Stark was much more touchy-feely than Captain Rogers.

Tony risked a glance at Coulson, but the man was as enigmatic as the Mona Lisa.

"How many casualties?" Rogers asked again, louder.

Stark hesitated. Coulson was the one who answered.

"We're estimating more than one hundred killed or injured on the offsite labs. We had moved two of the bat-aliens to the helicarrier, but they were taken out with minimal casualties. Less than twenty dead in China Town, thanks to the Avengers."

Those were terrible numbers, but it could have been so much worse in the city. It was twenty too many, but after the Battle of New York, Tony knew things could have been a lot worse. "And both sets of aliens went inactive again when the portal shut down?" Tony asked quickly.

"Yes." Coulson looked at him. "Which is why Shield believes it imperative to get to the bottom of this. And we want to know what this has to do with you, Mr. Stark."

That raised Tony's hackles. "Gee, I missed the fact aliens were attacking my dimension, too. Or that I'm marooned in a world where Stark Classic here is normal. Thanks for putting that together for me, Agent."

"Knock it off you two," Rogers said with more weariness than Tony had ever heard from him. Rogers gave a sort of shiver and leaned away from Stark to flick commands over the holoscreen. If his fingers trembled, no one said anything. "This was our second invasion, but it was their universes' first." He glanced at Tony, then frowned. "What are the chances your, uh, Shield will want to move the aliens to an offsite lab, too?"

Instantly Tony had the attention of the room, just the way he liked it. "Good," he said. "Fury will want to study them closer for weapons capability." And his Steve would surely argue against dumping them in the ocean, not if there was a chance to reason with them. But Tony knew better than to say that aloud. "More reason to get me back home ASAP."

With a few swipes of the holoscreen, Rogers brought up their most current projected model of the portal. "I combined the scans I got from Jocasta and, uh, Stark's Jarvis. This is our best representation of the portal." An image of an elongated funnel appeared in the air.

"Think of it as a cosmic elevator," Tony added.

Captain Stark crossed his arms over his impressive chest. "So, floor one: shoes and normal universes? Floor two: housewears, pantyhose, and me as Iron Man?"

"Kind of." Rogers tapped another few commands. Small, hair-like fissures branched out from the funnel. "These represent cracks in space-time -- you can't bore a hole without resulting damage, and every once in awhile you get something like this." Two fissures branched from each side of the funnel and glowed. "It's an artificial pathway to two universes, similar, but different like reflections of each other in a mirror."

"And Mr. Stark is from one of these?" Coulson asked. "Then why is this our second invasion and his first?"

"Our current theory is your universe is a 'floor' before mine." Tony waved a hand at the simulation. "This is a really simplistic--the transit portal must exist in at least six dimensions, not the three or four we're used to seeing. Creating these theoretical models are where Bruce Banner would come in handy , but Rogers tells me he's not around in this universe." Tony waved again. "But that's the jist."

Stark frowned at it. "It looks a little like Yggdrasill."

"The Asgard tree of life between the realms?" Coulson asked, cocking his head. "I can see it. Can it be reopened on our side?"

Tony exchanged a look with Rogers. "We're pretty sure it will reopen on its own. That's good news for me, because our universes are closely aligned. Getting back home should be just a matter of flying through the portal."

"Or you can end up in one of a hundred million other universes," Steve pointed out. They'd had this conversation already.

"Never know. The next one might have Natasha as Iron Man," Stark drawled, still frowning at the simulation. "Let me get this straight. These fellas take their traveling grudge match from universe to universe... why? For giggles?"

"They're _aliens_ ," Tony said. "Who knows? Thor's epic love of pop tarts is bizarre by any standard. And he's much more human-like than Rocky and the Bat Brothers."

"We need more data to level a guess," Steve sighed. "Last time it took 164 hours for the between portal openings -- a little less than a week. It probably will again. We'll be adjusting our suits to scan for any carrier messages. That's my theory on how the aliens know when to attack."

"When it opens, I'm out of here," Tony said. "This isn't my home, and you have no idea how much my Captain America can lecture. Imagine this," he gestured to Steve. "Six feet of patriotism."

The glare Stark leveled at him was fairly self righteous in itself.

"Before you leave, Shield wishes to debrief you," Coulson said. He spoke, as always, blandly enough, but his words made the room go still. Tony turned to him.

"Thanks but no thanks."

"Is that really necessary?" Stark asked Coulson.

"He may have knowledge of future crisis's Shield can get a jump on." Coulson glanced first at Stark, then at Tony. He lowered his voice. "I suspect medical will want a blood sample from him, Captain. They'll see this as an opportunity to compare you with your pre-serum body."

Tony did not like the sound of that. "Tell you what, when I get back I'll have Pepper send a copy of my genome over. I'm sure she has it in a file cabinet somewhere."

Stark stiffened, and Tony clearly saw a flash of pain in his eyes.

"Oh." Tony looked around, getting blank stares in return. "No Pepper here?"

"Not for seventy years," the Captain said.

And just like that, this universe seemed a lot less amusing and a lot more depressing. Tony couldn't imagine a world where Pepper wasn't running interference for Stark Industries -- or in his life at all. He felt bad for Stark, worse for Rogers because in his truly honest moments Tony knew three-quarters of the reason SI still stood was because of her. Running the company without Pepper was... unthinkable.

Stark seemed to shake himself. "Phil, the man's needed here. Steve's workspace is state of the art, but having another big brain to help him won't hurt."

Tony was a little taken aback by the sudden warmth in Stark's tone, and the way that Coulson looked at him and nodded in agreement. Then again, Coulson had always been a Captain America fanboy.

"In fact," Stark continued with a sly grin, nudging Coulson's side with an elbow. All buddy-buddy. "Tell Fury he's in Avenger's custody. He knows we'll keep an eye on him."

"That... may work," Coulson agreed. "I'll talk to Fury and see if I can hold him off for a least a few days."

Stark grinned brightly, as if he wasn't playing the agent like a harp. No, it wasn't just that... the two of them clearly got along. "Thanks, Phil. That's mighty big of you."

* * *

 

**O O O O**

* * *

 

 

By ten o'clock that night, Rogers was more or less slumped over his console, red-eyed and poking listlessly at data. He seemed to do that equally with both hands, perfectly at ease with his right as with his left. He'd become increasingly nonverbal -- not short, Rogers was never snappish or rude, even here -- but the person Tony was used to being the most invincible, looked terrifyingly vulnerable.

He had a bad feeling this was how his Steve looked at him sometimes.

And Rogers had been taking once an hour hits off that inhaler.

Tony made a show of leaning away from his own console and stretching. "Well, my simulations are set to auto-run for another few hours. How about we take a break?"

Instantly, Rogers straightened. The narrow-eyed glare he sent Tony's way was all Steve Rogers in any universe. "Why? You getting sleepy?" he asked with just a little belligerence.

Tony shrugged. "All work, no play makes Rogers a dull boy."

"There's a reason why the public doesn't suspect I'm Iron Man." He turned back to his own work, shoulders tight. "You can go, if you want."

Oh was that how it was? "I'm good." And he turned back to his own console.

Four hours later, Tony approached Rogers with a light blanket he'd snatched from a nearby couch. Rogers was asleep, head cradled on his arms, numbers ticking idly by on the holoscreen above his head.

Tony draped the blanket over his shoulders, then with a couple of pokes, set the tests to silently auto-run. Hopefully Rogers wouldn't shift in his sleep and fall off his stool, but Tony had a feeling he slept like this a lot. Tony's own back couldn't handle it. Then again he was about ten years older than Rogers in this universe.

One of Rogers' hands rested on the table, with the rescue inhaler loose in his grip. There were no pharmacy notes on the side. Whatever was inside, it was specialty made. Tony noted again the darkish, familiar liquid in the well.

A chlorophyll detox mixture converted into an inhalant?

Carefully, Tony brushed a piece of Roger's blond hair back to get a good look at the side of his neck. It looked normal: No veins darkened by palladium necrosis. Rogers had shown him his arc reactor earlier, too. The room hadn't been well-lit at the time, but Tony would have recognized darkened capillaries.

Frowning, Tony removed the inhaler from Roger's limp hand and depressed the button. It emitted a dark green cloud. He recognized the smell, too. Definitely a chlorophyll mixture. Actually, Tony had developed a taste for the stuff after the whole dying thing. Was Rogers the same? But asking Dum-E to add some chlorophyll (and raw egg) in his morning smoothie was a far cry from inhaling it all day.

Tony replaced the inhaler into Roger's hand and made his way to the door, pausing only to give his silently standing armor a pat on his way out.

* * *

 

**O O O O**

* * *

 

 

The Avengers mansion was much smaller than Stark Tower. Actually, it reminded him a little of Xavior's school -- he passed by a hallway of bedrooms he assumed were for the Avengers or for other guests.

The living room was empty at the late hour, as was the bar, which was stocked but didn't look well used. Tony poured himself two fingers of the most expensive scotch he could find.

As he drank, he considered: If he were looking for Captain America in his world, where would he start?

The answer was easy. And the fact that he found Captain Stark in the gym a few minutes later was both predictable and a little scary.

The Captain was laying on his back on a bench under a barbell machine with practically all of the weights in the room attached, as well as a few others hanging on by bungee cords. Even then, all his reps were smooth and unstrained. He wasn't even breathing hard.

"Like what you see, Stark?" the other Tony asked, which was creepy as hell as he was facing away and there weren't any mirrors in sight.

Tony shrugged. "What, lifting motorcycles full of chorus girls not good enough for this century?"

Stark grunted as he hefted the barbell to full extension and held it for the count of three. "Chorus girls, eh? Your Captain America sounds like a good time."

Oookay, it sounded like this Captain America hadn't been on the USO circuit. Made sense. Tony had more talents than any three (or four) people put together, but he couldn't sing.

He'd heard Steve sing a few times. He had a nice, mellow baritone, and had Tony thought it would have worked, he would have thrown a large chunk of cash at him to hear more.

"Aren't you supposed to have a spotter?" Tony asked instead, pushing that memory away. The feeling in his gut was akin to homesickness. "Safety first, Cap."

Stark snorted. Then, when the bar was at its full extension again, he switched to a one handed grip in the middle. Showing off. "You volunteering?"

"Sure. Give me an hour with a welding torch and some pulleys. I'll build you a machine that can catch that before it crushes your sternum."

" _Engineers_." He said the word in a sigh, but there was a strange undercurrent of warmth there, too. "I told Steve half the fun's in the danger. 'Sides, if it falls, I'll heal. It's what I do." But he hooked the bar (the metal practically groaned, he had so much weight on it) and rolled effortlessly into standing.

The two Starks approached each other like two stray cats meeting for the first time.

The man's shoulder to waist ratio must have been built by Erskine, because Stark could have given his Steve a run for his money. He was a touch broader than Steve in a few places, clearly shown under his white tank top. A little thicker overall in the torso. His face was the same Tony had seen staring back at him in the mirror at twenty-seven or so, minus the ironic cynicism.

Captain America in any universe had an air of authority, but there was something else to Stark. With Steve, Tony could almost believe the old joke about punching Hitler out because he was _that_ good, that solid. This Captain America in front of him gave off the air that he'd seen some serious shit and he wasn't above seeing more.

Stark looked at him for a long moment, then crossed his thick arms over his chest. "I don't suppose you've come just to jaw. This is the part where we compare notes?"

"Call it scientific curiosity," Tony said lightly. "I'm what you used to look like before the serum?"

Stark cocked his head, dark eyes sliding up Tony's body. "I was about a half-an-inch shorter, little scrawnier." His gaze fell to the arc reactor. "How's your heart?"

"Fine, except for the shrapnel trying to crawl into it."

"No defects?" Stark asked.

So that was something Captain Stark had in common with his Steve. "No, I'm healthy. Let me guess, you couldn't get enlisted?"

"Not with my bum heart. Didn't stop me from fighting, though."

"Fighting?"

Stark nodded. "I boxed, mostly, when it was legal. And fought dirty for side pay. They called me the mongrel back then. You know, half-Italian, half-Irish. Palled around with blacks. The whole shebang."

 _He'd been an old-timey prize fighter?_ Tony hadn't expected that. He had liked learning how to box from Happy, but that was a far cry from -- then again, engineering was his life. His existence. He'd never imagined what he would do without it, but now he had an answer: He'd fight.

Stark's eyes narrowed as he took in something about Tony. Then he nodded again. "You're sleeping with your Steve, too?"

It wasn't often someone managed to shock Tony. Figured it would only be himself. He jerked in surprise. "No. What? _What_?"

Stark just nodded, a smile twitching at the corner of his mouth. "Too bad." He turned to relieve the groaning weight machine, grabbing two weights in one hand at a time to stack them in a corner. "He's a tiger in the sack."

Tony's mind short-circuited a little at the image of that. He'd never had a size kink, but the thought of himself manhandling a smaller Steve was -- holy shit, _hot_. Not hotter than his Steve manhandling _him_ , though.

Then Tony realized what was going on. He pointed an accusing finger at Stark. "No, you don't get to play that game with me. I invented deflection from awkward questions via sex -- and what the fuck, you and _Steve_?"

If Tony were fucking Steve Rogers he'd be walking around with a grin on his face (and a permanent limp, probably), but why wasn't there any mirth in Stark's eyes?

"At times," Stark said.

Tony sucked in a half breath, thinking of the inhaler full of chlorophyll. "Not recently?"

The weights clinked as Stark stacked a few more in the corner. "He's a busy fella."

Yup. And erectile dysfunction was just one of the many delights of palladium poisoning.

Tony swallowed. "Let me ask you a question. Your Steve's a generous guy?"

"Sure."

"Gives away his things?" He paused. "Not running his company anymore?"

Stark narrowed his eyes. He set the last of the weights aside and hooked a thumb in his waistband, a casually intimidating pose. "He has his hands full with the Avengers. Only made sense that he took a step back."

Tony's stomach did a painful swoop. _Damn it._

Stark looked hard at him. "You're going somewhere with this."

Yes he was, and he didn't like how the puzzle pieces all fit into a glowing neon sign that spelled out palladium poisoning. Probably in the early stages, seeing as Rogers' veins weren't blackening, but still. Not good.

"Just trying to get a picture of the similarities between our universes," Tony said casually, and switched the subject. "You didn't sell war bonds for Senator Brandt."

It was Stark's turn to look honestly surprised. "Hell no. I told him to shove his idea where the sun don't shine. He shipped me off to Los Alamos -- that's where I met Joe."

"Joe?"

"Steve's father," he said. "He was one of the doctors there. Good man."

"Funny, that's what my Steve says about Howard."

"He said that?" A furrow developed between Stark's eyes. He shook his head. "No, Joe's nothing like Howard. He and I were in the lab when we intercepted intel about the 92nd infantry gone missing. Joe helped get me back on Brandt's good side to sneak me over there. Act all contrite-like. Brandt still gussied me up in the uniform, but it worked out in the end."

"I'll bet." Tony dragged his eyes up and down, appreciating the view all over again.

"You know all what I find strange?" Stark said in a sudden rush. "You're rich, you grow up with all the advantages of this time and tech, and you still--"

"What? End up as Tony Stark?" Tony paused and added. "Awesome?"

Stark smirked, though it had an edge to it. "I made myself this way."

"Newsflash," Tony said. "So did I." He paused. "I never thought I'd be the type to volunteer for the war, though. I'm not a soldier."

"Never said I was a good one." But Stark must have picked up on the unasked question because he added, "If you have a Captain America in your world, you know about the ice nap that got me here."

Tony's flinch was involuntary. He had called it an ice nap a couple times when the Avengers were newly formed as a team, and he had a bone or ten to pick with Steve. It hadn't been to be nice. And to hear himself talk about it told him a lot about how much Stark wanted this conversation. But it had to happen sometime.

"I know _my_ Captain America's story." Tony looked him straight in the eyes. No bullshit here. Well, no more than usual. "Little boy Orphan Annie plucks up enough gumption, or whatever you called it back in the day, and gets himself enlisted in a super secret government program." He paused. "But we aren't orphans."

"You're not wrong," Stark replied. He seemed to consider his answer for a moment, then shrugged as if to say 'what the hell'. "Howard owned a manufacturing business when I was a kid -- He fixed automobiles and such. We did well for awhile, but he lost it during the Great Depression. Then he became a good-for-nothing drunk."

Tony swallowed. "And Mom?"

"She left both of us before Howard finally managed to drink himself to death. Remarried, or so I hear." Stark's voice had taken on that deceptively mild quality again. Tony was going to have to watch it in himself -- it was a huge tell. "I have great-grandnieces running around somewhere."

Tony nodded. He didn't ever talk about his mother, not like he did his father. Even now as a fully grown man, he still thought back on his father with a mix of anger, fear, sadness and... yes, a little bit of hero-worship buried carefully way, way down below. His mother, Tony hardly knew at all. Though it was her smile he saw in the mirror.

Stark didn't ask Tony outright, just waited patiently, as if he knew Tony was going to give the answer he wanted to hear one way or the other. That was a Steve thing -- or maybe a greatest generation thing.

Tony glanced to the side. "I've just your typical poor-little-rich-boy story. Mom was too busy with charity functions to raise me. I was shipped off to boarding school at seven -- worked with Dad in Stark Industry labs on summer breaks." His shrug for a decade and a half of rejection and loneliness was well practiced. Scar tissue too thick to touch. "They both died in a car crash when I was at MIT. I was seventeen."

Stark nodded once. His eyes flicked down to Tony's arc reactor. "Got that lamplight in Afghanistan?"

"Yup." He tapped a finger nail against it to make a satisfying 'ting' sound.

Stark's look was sympathetic, but not pitying. "Rough country."

"Yes, thank you Captain Understatement. But I don't know what got your Steve there. _I_ did the playboy thing, pissed off enough board members and investors so that no one but Rhodey looked real hard when I disappeared." Tony saw Stark flinch at Rhodey's name, but plowed on. "But the Steve I know--and I think your Steve, too -- doesn't make those mistakes. Our mistakes." He paused and saw the agreement in Stark's eyes. "He's too good."

The look that passed between them was one of very clear understanding.

"You said it," the Captain said. "I wasn't here at the time, but I got the gist from the news reels--reports, on the websites. Steve's golden all through -- not the corporate moneyman type. He put his head in the sand, invented his little electronics and gizmos while the rest of the board ran the company. Then a man named Obadiah Stane wanted more power."

"Nice to know Obie's the same in every universe." Tony could hear the undercurrent of anger in his own voice.

Stark looked at him. "I told Steve he's trouble, and I'll tell you the same. Prison doesn't keep a man like that, a man craving power, down for long."

"He's dead," Tony said flatly.

Stark seemed surprised for a moment. Then he gave a grim nod. "Good."

"One other difference between your world and mine." He tilted his head, looking up at Stark. "In my world -- everyone knows I'm Iron Man."

That surprised Stark into a laugh. "Hell, I could never do anything by half, could I?"

"No, I should have died in that cave," he said and it felt like the honesty was going to sear his throat. "I've been given a second chance, and I wasn't going to be quiet about it."

That got another chuckle out of Stark. Tony had the feeling he hadn't been quiet or dignified about things, either.

They had a lot more to compare, but later. This had been a good start.

Stark seemed to feel the same. He made to leave, but paused to clap Tony heavily on the shoulder. "You do what you want with your Steve, but if you're thinking of making a move on mine, you and I are going to have words."

Wow. Jealousy issues or abandonment issues? Probably both. Refusing to be intimidated, Tony waved a dismissive hand at him. "I'm still trying to figure out how you got Captain Repression--no that doesn't work here, Iron Repression? -- in the sack."

"Our Steves must be different. He made his move on me."

 _Hot_ , Tony's brain helpfully supplied again. Then he remembered the palladium poisoning. It seemed this Stark didn't know about it, which wasn't a surprise. Tony hadn't exactly been ready to share when he knew he was dying. He'd be sure to leave behind the schematics for the vibranium partial accelerator as a thank you gift before he got home. Steve would fix his little problem, and Captain Stark would get over his insecurities.

"I don't want him. He's Iron Man -- I can't figure out if it would be masturbation or incest."

"I think you're confusing you and me," Stark said.

"Oh Captain," Tony purred. He half-expected the other man to blush like Steve usually did. But Stark only gave him his best leer.

"Sorry flyboy," he said, hand sliding off Tony's shoulder as he walked away. "I'm taken."

 

* * *

 

**O O O O**

* * *

  
 

Tony woke alone in a comfortable, but unfamiliar bed in an unfamiliar guest room. There was no Jarvis to tell him the time and weather. And for one dizzying moment he stared up at the ceiling and felt a hot clench of homesickness in his gut.

How many times as a child had Howard told Captain America war stories, saying he was the best man he knew, and that Tony ought to strive to be more like him?

Oh, the irony. It burned.

Rogers and Stark were together in this world -- or somewhat. Maybe fuck buddies? But Stark had come off as invested. Rogers never mentioned anything to Tony in the lab yesterday, but it figured he wouldn't be the type to kiss and tell.

Then again, there was a lot the little guy was keeping to himself. Even early stage palladium poisoning was no picnic, which was why Tony had hidden it from Pepper. Rogers wouldn't know Tony had a cure -- he couldn't know Tony knew about the poisoning at all. The first symptoms were easy to dismiss.

Tony pushed back the blankets and shuffled to a nearby dresser, which was stocked with generic clothing of different sizes. The alarm clock on the nightstand (a regular one, what the hell Rogers, what was the use of being a genius inventor if you didn't show it off?) said it was just past eight. Past time for most of his tests to complete.

He'd share the deets on the wonders of vibranium when he had a solid way back to his world. Until then, Tony would have something in his back pocket in case Shield came calling again and Captain Stark couldn't stop them.

Freshly dressed and showered, Tony padded down the hallway toward the scent of coffee. Another snippet of last night's talk with his counterpart came back to him: Rogers had been the one to make the first move.

He wondered if it was an Iron Man thing, and how his Steve would react.

One thing was for sure, if Tony hit the lottery and Steve was attracted to him, wanted to give _them_ a try... Tony would make sure Steve knew where he stood in his heart. Tony liked this version of Rogers, but he hadn't liked the uncertain, insecure look behind Stark's eyes when he'd talked about their relationship.

Maybe when the time came to get the hell out of Dodge and go back home, Tony would share that tidbit with Rogers, too.

 

* * *

 

**O O O O**

* * *

 

 

Steve Rogers listened to grunge when he worked. He had Nirvana's Nevermind on repeat.

When Tony got home, he was going to have Jarvis ban all things Kurt Cobain from the tower's database.

"You know," he said over the Seattle-gray lyrics of Smells like Teen Spirit, "I liked Weird Al's version better."

"What are you, twelve?" Rogers answered. Tony couldn't tell if he had ever gone back to his own room last night -- he'd probably slept in the workshop, got up, then showered and came back. Not that Tony knew what that was like.

But there were deep shadows under his eyes that spoke of stress, and he used his inhaler on the hour, every hour.

"AC/DC, Sabbath, Metallica. These are the classics, Rogers. There's a whole other musical world out there that doesn't involve hacky sacks and rain."

Rogers lips twitched up in the corner. "I could put on Korn if you want..."

"Korn," Tony scoffed. "Isn't that a little dark for you?"

The song switched overhead to Pearl Jam, and his feelings for that band must have shown on his face because Rogers took pity on him.

"Jocasta, play the best of the Rolling Stones."

Finally, something they could agree on.

 

* * *

**O O O O**

* * *

 

 

Two hours later, they had good news and bad news. The good news was they had a more complete model of the portal, of how it worked if not how to reopen one of their own. The bad news -- the _really_ bad news -- was it was only a matter of time until it reopened, and the reason why the aliens had arrived in the first place was still a mystery. Hopefully, Thor would be back from Asgard soon with some answers. 

Tony was so busy fine tuning an equation to prove the stability of the portal's event horizon, he didn't hear the door to the workshop slide open.

"That's him?" said a voice behind him.

Tony turned and nearly leapt out of his own skin. The Winter Soldier stood not three feet away, looking impassively at Tony.

"Jesus!" Tony may or may not have flailed a little, his back hitting against the desk.

The Winter Soldier took a sip out of a Starbucks cup, looking distinctly unimpressed. "You're a lot jumpier than I expected."

It took Tony a moment or two to collect his wits, though he may not ever get back his dignity again. No, this wasn't The Winter Soldier. The man had short brown hair -- styled and lightly gelled-- and wore a pressed shirt and modern, clearly tailored skinny slacks. Holy shit. Bucky Barnes. This was the guy Steve was always yammering about.

"And you've got one less robot arm than usual," Tony snapped. He reached out to poke Bucky's left arm. Felt real enough.

Bucky knocked his hand away. "Watch your motor oil fingers. This shirt's from the forzieri collection."

"Robot arm?" Rogers repeated. He gave Bucky a sharp look and came around to his side, as if to shield him from Tony -- which was ridiculous. There must have been eight inches of height between them. "This is Bucky Barnes, my PA," Steve said, and only then did Tony register the slick folders Barnes was carrying in the cook of one arm. Of course. Pepper wasn't here. He should have guessed...

"Anyone other than me hear about The Winter Soldier? No?" Tony looked at their blank faces. "Okay this world is weird. You're weird. A good kind, but really strange."

"Is Winter Soldier codename for an evil lawyer in your world or something, Stark?" Bucky asked. Then paused. "Do I work for the IRS?"

Was that... a bluetooth in his ear? Wow. Okay, so definitely not the Russian asshole who had nearly cost Steve his life and the rest of the Avengers their sanity trying to talk Steve out of capturing him alive and rehabbing him.

Tony's laugh was dead of humor. "The Winter Soldier's a Russian master assassin. Last time we met, he gave me this." He rolled up his sleeve to show a purpling straight line scar. "He jammed a knife straight through my armor."

Bucky glanced at it. Then his eyes went flat and dead in a way that sent a lightning zip of fear down Tony's spine. "You're saying I missed."

Tony took a step back.

"Bucky, don't be an ass," Rogers said.

Then the dead-eyed Winter Soldier was gone, and Bucky Barnes was back, with a sly sort of grin. "Sorry Boss," he said to Rogers, then winked at Tony before turning to set down his folders.

Tony glared after him. Fuck, he was off his game if he was allowing himself to be one upped by a man named _Bucky_.

Rogers didn't look amused. "Jocasta, bring up all references of the Winter Soldier," he said and turned to one of the holoscreens. "I want to see if he exists in this world."

Turned out, just like in Tony's universe, the Winter Soldier did exist. Though he worked mostly in shadow -- he was more myth than person, only seen from afar. The only picture was a grainy photo of a tall and skinny man, the metal arm glinting in the sun.

"Watch out for him," Tony said lowly. "When they send him to take out Captain America -- and they will -- don't underestimate that arm. Jarvis calculated a crush grip of 3,700 pounds per square inch."

Bucky whistled. "That's as much as an alligator bite." He shrugged when they gave him a look. "What, I watch a lot of Animal Planet, okay?"

Rogers pursed his lips. "And your Steve has to fight him."

"It rips his guts out every time." And Tony usually had to pick up the pieces afterward. God, how he wished Steve could get drunk. They'd go up to the rooftop and just look out, just talk. Steve blamed himself, which was ridiculous. "He used to be my Steve's best friend, but got captured back in the forties and cryogenically frozen. We think. We're still a little fuzzy on the details, and he's usually too busy trying to _kill_ Steve to tell us."

Bucky had come around to the holoscreen to get a good look at the Winter Soldier picture. He turned away with a scowl. "I don't get it. I'm not even Russian, my parents were Irish."

"I don't think that mattered to the brainwashing committee," Tony said. But that did raise a good point. He shrugged, turning away. "So if the Winter Soldier isn't Barnes here, who--" He broke off.

Rogers wasn't looking at him directly in the eye.

Tony turned back to the grainy shot. The hair was cut short, and it was more of a silhouette than a picture -- no skin showing. "It's Rhodey, isn't it?" he asked flatly.

Rogers shook his head. "James Rhodes died in the fifties."

He jerked a thumb at Bucky. "You thought he was dead."

And for one horrible second, Tony understood Steve's desire to capture, not kill, the Winter Soldier all too well. If their positions were reversed... and they _were_ , here, weren't they?

He couldn't think about it. Not now. Tony forced his eyes away from the holoscreen and said lightly, "We should start a list. It's not just Steve and I who's switched, but Barnes, Jarvis -- Does Jarvis count?"

"I think so," Steve said. "Is Jocasta a part of your world?"

"Not that I know of.." He ticked it off on his fingers. "My father, your father, Pepper, and Peggy Carter. But Nat, Clint, Bruce and Thor are all the same. For the most part."

"Thor is an alien."

Tony waved a hand. "Details."

"Kind of important details, Stark," Bucky said. He looked like he still had a hard time believing he was a killer in another world. "I wouldn't... Boss--Steve, you know I'd never..."

"Barnes is possibly brainwashed in my world," Tony said.

"He'd have to be," Bucky said seriously, then seemed to shake himself. "Anyway, the actual reason I came down is you have some papers to sign." He turned and grabbed the folders.

Tony drifted away and back to his work station as Bucky went through invoices, which Rogers dutifully signed.

"And when's the last time you ate?" Bucky asked with good natured frustration that Tony was used to hearing from other PA's. "I'm ordering sandwiches from Jimmy John's down here. So help me, if you don't get real food into you, I'm going Winter Soldier on your ass." Bucky paused and he and Rogers both looked guiltily across the room at Tony. "Too soon?"

Yes, it was. But more importantly, in all Steve's stories about the trouble he and Bucky got up to being ragamuffins in the 30's, he never mentioned how inappropriately hilarious he was. Tony waved him off, and shortly after Bucky went back to haranguing Rogers about upcoming meetings.

Tony could get to like the guy.

 

 

* * *

 

**O O O O**

* * *

 

Two days later, Tony found himself in the main kitchen, sitting at a farmer's style dining table that could have fit a dozen, plus Thor. Bucky had come down to the workshop again and summarily kicked him out, wanting to talk private RI business with Steve. Normally, Tony would have objected, but he needed a coffee break. And since Rogers didn't have a decent coffee machine there, here he was.

Turned out their local friendly Spiderman had also come to quite literally raid the kitchen. (If normal raiding meant perching, still in uniform, in a ceiling corner and zipping food out of the refrigerator by way of his webslingers -- the guy was weirder than Clint with his arrows.)

"Are you Hank Pym?" Tony said.

"Nope." Spiderman snagged a box of pop tarts from the counter and stuck it to a web already groaning with other items.

"Johnny Storm -- Wait, he'd never be able to keep the mask on without mugging for a camera, I should know. Zeke Stane?"

"No and no."

"Give me a hint. Who am I going to tell? I don't even belong to this universe."

"Sorry," Spiderman almost sounded it, "But I have to keep this one close to the chest."

"I'll pay you one-thousand dollars, cold hard cash."

This actually gave Spiderman a pause. He cocked his head. "Wait, you have that right now?"

He waved that aside. "I'll get into Cap's bank account. I'm a dead ringer for him."

"Cap knows my identity," he admitted sheepishly.

Tony set down his coffee mug. "So let me get this straight. You trust me, but you don't trust _me_?"

"Speak of the devil and he shall appear," said a very familiar voice as Captain Stark strode into the kitchen. He was rocking a pair of jeans that were a size too large and a Hawaiian shirt. Shower fresh, he was rubbing a towel over his dark hair. He waved at Spiderman, and nodded to Tony. "What are you fellas talking about?"

"He's trying to guess my secret identity, and missing by a mile," Spiderman said.

Tony decided it was time to throw out all the stops. "Bruce Banner, Tommy Riordan, Sam Wilson, John Blake, Galaga Guy, that one asshole who calls himself Dead Pool, Keanu Reeves, Matt Murdock, Ty Pennington, Brian Braddock."

"I don't even know who half those people are," said Spiderman cheerfully.

"I knew a man named Brian Braddock, back in the war. Interesting fella," Stark said, then looked at Spiderman. "And you don't say a word. Stark here told the world he was Iron Man."

"Harsh, but technically true," Tony said.

Spiderman slipped down the wall by a foot out of shock. "Really?" he squawked.

"I was Time's person of the year," Tony said. "Worth it."

Stark poured himself some coffee. He took it black, no cream or sugar. Just like Tony. "I was too, post-mortem in 1945."

Spiderman finally managed to snag an unopened gallon of milk from the refrigerator, using three different web strands. It was a little impressive. He added it to the web collection of a box of pancake mix, a tub of mustard, two brands of cereal, and a sack of instant rice. "Welp, it's been fun, but I got uh, stuff to do."

Tony narrowed his eyes. "Work type stuff, or school type stuff? How old are you?"

"Uh, gotta go," Spiderman said, which was all the answer Tony needed. "See you Captain and Mini-Captain." Spiderman bounced down from the wall, a web-sack full of groceries in hand, and somersaulted out an open window.

Stark chuckled. "He's a fun kid. And no, I ain't telling you his identity."

Tony glanced to the open window. Spiderman might be hanging outside, still listening, but he doubted it. "If he's on the team and still in the position where he needs to fill his cabinets--"

"--Steve can afford it--"

"So can I," he said firmly. "There's no Spiderman in my universe, but there still might be a kid who could use a little help."

Stark took another sip, clearly mulling it over. "He's smart," he said at last. "Not Steve-smart, but good with sciences. No one likes charity, even from a rich man, but even if he doesn't have powers in your universe, you still might get some use outta him. I'll ask him."

"Do it fast," Tony said. "When that portal opens, I'm leaving. I'll only have a limited window--"

A polite chime echoed through the room. "Excuse me, sirs," Jocasta said, her tone carrying just a hint of urgency. "There is an urgent medical situation in Mr. Rogers' workshop. Mr. Barnes has requested I contact an ambulance, but Mr. Rogers has overwritten my protocols--"

By the time Tony had set down his coffee, Stark was already out the door.

Tony ran full pelt. When he arrived in the workshop, Stark was kneeling beside a collapsed Rogers. Bucky was at his other side.

"--and he just fainted." Bucky was practically wringing his hands. "I had to call an ambulance by phone. Jocasta refused--"

Rogers's breaths were coming out in harsh, rattling wheezes. "I'm fine," he gasped, so pale his skin had taken on a grayish twinge, and twice as sweaty. "I just.. Head rush."

He tried to sit up, but Stark put one large hand on him. "Head rush, my foot. Stay down."

There was a chemical, ozone smell to the air. One that Tony recognized from experience. He squeezed in beside Stark and put his hand over Roger's arc reactor. Too warm.

"His arc core is burning out," Tony said. "It's dumping metallic residue faster than his body can handle. Rogers, you need a replacement."

Roger's blue gaze locked on him. Tony could see the stubbornness there, that he still wanted to lie and convince everyone he was fine. Maybe get a private moment to change out the core himself.

"His what?" Stark demanded. "What's going on?"

Tony ignored him. "The time for denial is over, Rogers."

At last, Rogers nodded and wheezed. "...Casta, disengage core... security drawer... Rogers-Omega-Five..." Rogers broke off, arched and gasping. His eyes rolled back into his head.

"Steve!" Stark felt for a pulse, but Tony could see it pounding in the thick artery in his neck. Too fast. To hard. He was tipping into cardiac arrest, and his body was in full freak-out mode.

Tony knew how that felt, too.

"Do you know where he keeps his spares?" Tony asked Bucky. When Bucky mutely shook his head, his eyes wide, Tony turned to his suit, which still stood a silent sentinel in the corner. "Jarvis!" he barked and his Iron Man armor's eyes flashed into brilliance. "Scan the room. Best guess where he keeps 'em."

There was silence for the space of five long seconds, then the suit lifted one arm to point dead ahead to an unobtrusive steel cabinet. "Second drawer down, sir. It is engaged by a number of biometric locks."

Tony rose and with a twist and a click, unhinged the right arm and slipped his own in. "Thanks buddy." Then he aimed at the top drawer and creating a hole just above the cores.

The metal had been weakened by the blast. Tony clenched his fist and smashed into it. A rain of small, red palladium cores fell to the floor. Other than the different color, the cores looked exactly as his own did. Tony scooped one up and went back. Rogers was completely unconscious, his lips bluish.

"Left up his shirt," Tony said.

Stark tore it down the middle, instead. Tony twisted off the flesh-colored cap over the arc reactor to reveal a dull red light. The color looked garish, as if he were looking at Roger's heart.

Tony could count the ribs in Roger's chest, though there was no sign at all of blackening veins. But if his cores were at the point of giving out...

Luckily, the reactor worked the same way his own did -- Tony had to turn it clockwise instead of counterclockwise. The old core, when he removed it, was smoking slightly but only half-slagged. Rogers shouldn't be having this severe of a reaction.

Bucky had a look of horror on his face. "That was inside him?"

Deja-vu. "Yup." Tony slid the new one in and closed the reactor. It glowed a dull red. Rogers twitched when the new core was shoved back into place, he dragged in a full breath. Then another.

"Jesus, Mary and Joseph," Stark muttered, stroking Roger's hair back from his face again and again. "What the hell is going on?"

Tony looked at the half-melted core, then again at Steve's thin, but unmarked chest. "Palladium poisoning," Tony said. His hands were shaking -- shock and his own bad memories, and the churning feeling he'd made a grave mistake by keeping the secret of vibranium to himself. "It's killing him, but I don't know how."

 

 

* * *

 

Earth Prime

* * *

 

  

"The cadaver dogs have hit on another scent, Captain," Maria Hill said over Shield comm lines "Their handlers need everyone to pull back to let them do their work."

Steve's stomach swooped, but he forced himself to nod. He'd already been through this process several times over the last few days. The search and rescue teams had to clear out to let the dogs work through the worst of the shattered building and pinpoint the scent.

"One second." He heaved a steel I-Beam up, and turning, tossed it twenty feet to land in a pile of already picked through debris. All that was left of a fifteen story building, which once had a mural of a community garden painted on the side.

Somewhere under the tons of concrete and scraps was probably Tony Stark.

Steve hoped to God he was still alive -- Bruce had Jarvis run the numbers. The suit might have survived the crushing force -- but as the hours dragged into days without communication it became less likely.

Tony's last words kept playing out in his head during quiet moments and in his sleep. The building was coming down. One of the rock aliens had tangled with the Hulk and lost its balance -- it's roar had shaken the marrow in Steve's bones as he rolled into the bottom level of the building, taking out all the support structures.

 

_"The building's coming down!" Steve had yelled. "Get clear, Hawkeye! Tony, where are you?"_

_"Shit! Hold on, Cap! I'm coming!" Tony had yelled._

_Steve had scanned the sky, but he was no where in site. "Tony, answer me!" Then Steve looked in horror at the crumbling building and put it together. "Get out of there!"_

_"No--" Tony's voice fell into static._

 

 

And Steve had been too far away to do anything but watch as the building collapsed.

 _Please_ , he thought for the hundredth time as he exited the debris field. _I can't bury another friend._

Nightmares of Tony calling out to him, of Steve switching to their private communication line and hearing nothing, had replaced the ones where Bucky fell from the train.

He wasn't sure he was ready to examine what that said about him.

Steve spied Clint among the exiting search team, as grim and dusty as the rest. Natasha was around there somewhere, too, and Fury had talked the Air Force into pulling War Machine from his assignment overseas to assist in case the Avengers needed aerial support. Meanwhile Bruce was working with Jarvis at the tower, following up on the other armor theory. No one had seen it, but Tony had been chasing _something_.

The invading aliens had frozen in place from the moment the building had fallen. As still as statues, and about as alive. Shield removed them to an off-site lab for further testing, but they were as perplexed as anyone. Mysteries upon mysteries.

Steve had sent Thor to Asgard. Maybe he could get some answers from his father and mother.

Did it make Steve a terrible person if he secretly hoped Tony was captured rather than killed, knowing what had happened to him in Afghanistan? Steve wasn't sure, but as more bodies were pulled from the rubble, the hope Tony was not here -- and was somewhere his team could rescue him -- grew.

It took forty-five minutes for the word to come down the line: The dogs found the remains of another person who was either unable or unwilling to evacuate in time. Not Tony.

The mix of emotions he felt at that was both bitter and confusing. Steve wasn't sure about many things right now, but he vowed if he somehow got Tony back alive... well. He didn't plan on letting him go anytime soon.

 

**Notes for the Chapter:**

> Comments and crit always welcome. :)


	3. Chapter 3

**Notes for the Chapter:**

> A note about how long it takes to make a particle reactor. When I outlined this plot I thought it took Tony a couple weeks to make it -- which was condensed with creative movie editing -- but on a recent rewatch I realized Tony actually did it in, like, one afternoon. Whoops? But the plot must go on. So I'm hand-waving that part of the IM2 timeline. :)

 

* * *

 

_Scrape... Scrape... Scrape..._

Tony tapped his fingers on his thighs, trying and failing not to look as Natasha sat sideways in a chair across from him in the tiny waiting room. He had no idea where she'd gotten the whet stone she was using to sharpen her knives, though this was a Shield medical facility. They probably had them in extra storage rooms. 

"You're not intimidating," Tony lied. "Not intimidated."

Natasha's smile was only visible to those who knew her.

"The you in my universe does the same thing," Tony said. "It's not even original, just so you know."

She slowly dragged the flat of the knife across the stone.

Tony lurched to his feet, swinging his arms back and forth.

"This is a waste of time," he said. "I should be in there. I've been through this before, got the T-Shirt to match."

"Is that so?" she asked, the knife paused over the stone. Yeah, he had her attention.

"You injected me with lithium dioxide. In the neck," he added, because that was the important thing.

She looked at him full on for the first time. "Did you deserve it?"

"No. Yes. Sorta? You were a triple imposter. I was..." he waved his hand in the air, "dying. It wasn't my best week."

The waiting room door swooshed open without ceremony, and Agent Coulson appeared. Oh damn. One look on his face, and Tony had a feeling he wasn't leaving Triskelion medical anytime soon.

"I need a moment alone with Stark," Coulson said to Natasha.

 _Don't go_ , Tony wanted to say. And that's where his life was at; he felt better in the knife-wielding agent's presence than facing down Coulson alone.

But it wasn't like he was going to let them know he was, in fact, intimidated. He sat and crossed one leg over the other. "So three hours later, you decide to ask the guy who actually has gone through this before? Our government at work, ladies and gentlemen."

Coulson took Nat's vacated seat. "So you knew about Steve's palladium poisoning."

"I had suspicions," Tony said and winced when Coulson's face remained bland. Unimpressed. "I was pretty sure."

Coulson looked him up and down. "I can't help but notice you're still alive."

Feeling jittery, Tony stood again. It should have put him in a position of power in the room, but it didn't help. Coulson was like that. "I invented -- _reinvented_ a new element."

"How?" Coulson asked.

Tony shrugged. He didn't feel like sharing the entire story. Least of all because Fury _still_ found opportunities to hold it over him, as if Tony owed Shield for keeping his father's notes and videos from him. "By being a genius. Give me a few weeks to build a particle accelerator, he'll be as good as new. Incidentally, the new reactor stops the damage cold."

"Steve doesn't have weeks," Captain Stark said from the half-open door. Tony whirled. Je-sus, the big guy was quiet when he wanted to be.

He wasn't the only one caught unawares. Coulson turned to Stark and frowned. "Captain, you and I agreed I would handle this."

"You agreed, sure," Stark said to Coulson. "Bucky's with Steve. He'll fetch me when he wakes." He took a step into the room and shut the door behind him, coiled strength in every motion. If Coulson gave the impression he had the power in the room, Captain Stark seemed to suck out all the space.

"What do you mean?" Tony looked from Stark to Coulson and back again. "It's early onset. He doesn't have the symptoms."

"He's been hiding it--masking it all with some concoction he brewed up," Stark said. "But it hasn't stopped the damage. His liver's shot, his lungs are building up fluid, his heart--" He stopped, running a hand down his face. "The docs say he's probably not getting out of the room."

Tony had to turn away and take a few steps back to get a moment of air. He turned back and met Stark's direct gaze. "I didn't know."

"Then he had us both fooled," Stark said darkly.

Coulson said, "How long will it take for you to recreate this particle accelerator?"

"Without Jarvis?" Tony shook his head and did some mental calculations. "I can do most from memory, but it's not something a normal lab is set up for. Most of the parts need to be manufactured from scratch. Some of the materials are--" illegal for non-government entities to own, "--rare. Vibranium is tricky to manufacture into a useable state, harder to control."

"Vibranium? Like in my shield?" Stark looked hard at him. "If you need a piece of my shield, you have it."

Tony shook his head. "That's a vibranium alloy -- I'd have to separate the pure vibranium out, which would take extra time _and_ completely destroy your shield in the process. We're working in a measure of elemental atoms. There's enough free floating around to build a new reactor-- Wait, hold on." Tony snapped his fingers as his mind made a leap. "The other day, you said Roger's father was a doctor. PhD or MD?"

Stark blinked. "Joe was a physician."

"Son of a bitch," Tony muttered. "That's how he did it." Coulson and Stark both had blank looks on their faces. Tony flapped a hand at them. "I was wondering--I reinterpreted my dad's notes for the new reactor, but Rogers must have done the same from his father's research to reverse or mask his symptoms for as long as possible. I _thought_ he was cycling his suit low. He was running everything with a fraction of the power to avoid toxic buildup."

Stark looked at him, unimpressed. Well, he wasn't an engineer. He didn't realize the sheer enormity of power consumption savings Rogers had accomplished. The... absolute genius behind it. The little sneak. He'd always had a feeling Steve was the quietly devious type.

"How long will it take to rebuild the reactor?" Coulson asked again.

"It took me just over fifteen days the first time."

"You have seven," Stark said. He took one single step to Tony, and it was enough to crowd him. "And you're putting everything else aside for this, you understand me? You _knew_ something was wrong, but you said nothing. You aren't going home until you see this through."

Tony jutted out his chin, but he couldn't deny it. "Fine," he said. "Yes. But I'm going to need full access to Rogers' computers, and a large amount of funds to purchase what I can't build."

"Bucky will help with that," Stark said with the air of a commander belting out orders. That was so strange.

Coulson cleared his throat. "If there's anything Shield can do--"

" _No_." Tony hadn't meant for the word to come out so forcefully. Coulson and Stark frowned at him, and he reigned in the impulse to blab about how Shield's counterparts leveraged the favor he owed him to agree to build repulser tech they then used for Project Insight. That would be something he'd share with Rogers alone, later. So he switched tactics. "If I'm focusing on the particle accelerator, I'm not focusing on the portal. Rogers and I were sure that was key to stopping these invasions. I'll be transmitting our research to your remaining Shield labs. The more eyes on this, the better."

Stark visibly hesitated, then nodded once. "Steve has an intern he likes named Peter Parker. I'll send him your way. He'll help."

Probably some sort of spy, then. Tony opened his mouth to object, but just then someone knocked, and Bucky poked his head around the door. He stepped in when he saw all three of them there.

"Steve's awake. The doctor wants to talk to him." He looked at Stark. "Tony, do you--"

"Yeah." Stark turned to clap Bucky on the shoulder, then jerked his head to Tony. "He says he has a way to help Steve. Do what you can, eh, Buck?"

Then he walked out, leaving Tony with Agent Agent, The Winter Soldier's hipster double, and soon-to-be seen Peter alliteration Parker all working to build a radioactive particle accelerator from scratch in record time. Great. Fantastic.

This was going to be _so much_ fun.

 

 

* * *

 

****

 

* * *

 

 

For the second time in his life, Steve woke hooked to medical equipment, a bone deep pain throbbing through his chest, and the knowledge that he had _royally_ fucked up. But this was a Shield medical facility, not a cave in Afghanistan, and this time it was Bucky by his side, not Yinsen.

"Welcome back to the land of the living." Bucky's smile had enough of a wobbly edge to it to tell Steve that his secret was out.

Steve leaned back into his pillow, taking inventory of the situation. There was some sort of a tube under his nose, feeding him oxygen, an IV in his arm, and the skin around his arc reactor felt hot and swollen.

"What happened?" he asked.

"I gave you the projections for next month's earnings, and you passed out," Bucky's voice took on a strained edge. "They weren't _that_ bad."

Oh yeah. He remembered some of that, as well as Iron Tony replacing the arc reactor core in Steve's chest. " _The time for denial is over, Rogers_."

So he'd known all along.

"Steve." Bucky pressed a hand to his shoulder, regaining his attention. "Tony wanted to know when you woke up. I'll be right back, kay? Don't go passing out on us again."

His head was muzzy from whatever drugs they were pumping into the IV. And for a moment, Steve wasn't sure which Tony he was talking about. But of course it had to be the Captain, which meant _he_ now knew about the palladium poisoning too, and... God--Steve didn't know if he could face him like this.

Clenching his jaw, he nodded anyway.

Sure enough, Captain Tony Stark walked through the doorway a few minutes later, a grim looking doctor in Shield medical clothing along with him. Bucky was nowhere to be seen.

Steve couldn't meet Tony's eyes, just stared impassively at a spot on his blanket as the doctor rattled off everything Steve had already figured out nine months ago: There was no way to remove his arc reactor without shards of shrapnel slicing into his heart and major arteries. Meanwhile, the heavy metal buildup from the palladium core was affecting his liver, his blood pressure was off the charts, his lungs were failing, blah, blah, blah, based on his current blood toxicity levels, he had maybe two weeks to live.

_Two weeks._

Steve blinked and looked up at the doctor, his mouth pulling to the side in a smile he didn't really feel. "I thought I had a little longer. A couple months, maybe."

Tony grunted as if he'd been gut-punched.

The doctor's face pinched. "Our blood work results indicate high levels of lithium dioxide. You've been managing your symptoms?"

Time to put all his cards on the table. "Along with chlorophyll as an inhalant. I noticed my asthma was acting up -- it helped, and chlorophyll is a detoxifier."

"Not for these amounts." The doctor notated something on his chart. "We'll have to wean you off the lithium dioxide. It's not recommended for long term use."

Steve laughed at that, and it hurt. "What, exactly, is long term about my situation, doctor?"

Tony spoke for the first time. "Stark has a cure."

Steve's head snapped up to stare at him. "What?"

"You'll notice he's been running around being Iron Man, in his world."

Steve had, of course. He thought for some reason the poisoning hadn't progressed as quickly -- that Iron Tony didn't know yet. The whole thing had been eating at Steve over the last few days, trying to figure out how best to bring it up.

"How?" he asked.

"Apparently," Tony drawled, "Vibranium isn't just good for deflecting bullets and bashing heads."

"Vibranium?" His mind whirled. "But... that element barely exists, outside your shield. All the work on it has been theoretical -- it's the rarest element on the planet." And God help him, he didn't even _think_ about testing it as a possible solution.

Steve pushed his blanket back. "Help me out of these wires. I need--"

"Mr. Rogers, that's not advisable," the doctor said.

Ignoring him, he sat up, and his vision darkened around the edges. His chest hurt -- a sharp, stabbing pain that felt like his lungs were squeezed down to the size of a straw. He clutched at his arc reactor, dragging a breath in as a wheeze.

He heard Tony tell the doctor to leave them alone, that Steve wasn't going anywhere. And damn him, he was right. Steve laid back down, trying to catch his breath. The tightness eased after a few moments, but all his joints ached with a raw, thrumming pain.

Tony took a seat in the visitor's chair nearby. "I've sent Stark off to get started -- Bucky's gone with him to give him access to Jocasta. Apparently, they'll need to manufacture a lot of their do-dads fresh."

Steve nodded and closed his eyes, focusing on getting his breathing under control. He hated feeling this way, hated being weak. He'd had enough of it as a child before he got his asthma under control.

When he opened his eyes again, Tony was fidgeting.

"So, dying. That's not fun." Tony used his blasé voice. The one that screamed he didn't care when he did. He didn't even look Steve in the eye. "This is your big secret? This is why you've been so... distant?"

Steve swallowed. "Yes."

"Was it worth it?" Tony asked. He looked up and oh, there it was, full-fledged Captain America disappointment in his brown eyes. Disappointment and hurt. It cleaved Steve down to his arc reactor. "Steve, if I knew--"

"You would have kicked me off the team," Steve said hollowly.

Tony's lips turned down at the corners. "You must think real low of me, Rogers."

"I'm realistic. And I thought... I had more time left. I had my father's notes--I thought I could... carry on. For awhile longer."

"You're an engineer for Heaven's sake, not a doctor," Tony said, tensing, and the arm of the chair snapped under his grip. Irritated, Tony lifted his hand and the broken piece flopped uselessly to the side. "Damn it all," he muttered, rising. There was color flushing his cheeks. He turned to the door, clearly ready to leave.

"Tony..." Steve hated how plaintive his voice sounded. He took a shuttering breath, blinking dry eyes, knowing he had no right to ask, but he couldn't stop. "Don't go."

Tony turned back to him. "Don't go? That's rich. You're the one who stepped away from _us_ without telling me why."

"I--"

"I thought it was something I did. I thought--" Tony hesitated then shot a glance over his shoulder as if he were shamed. "I thought you were hitting on my counterpart. Two Iron Men--you two were like peas in a pod, yet you wouldn't give me the time of day."

Steve took a sharp breath he immediately regretted. "No. No, never."

"And it turns out you were hiding this from me. That's not better, Shellhead."

"I knew you'd react badly." Steve regretted the words the moment they were out.

Tony's mouth pinched. "You didn't trust me."

"I didn't know how to tell you--"

"How's this? Tony: I'm dying. Three little words. You could even plan it out -- you're good with plans. Sit me down and tell me over a nice omelet. But you didn't trust that I wouldn't--" He exhaled a long breath. "I know I'm a smart man in my own right, but -- not like you, not like the _other_ me. I don't get all the crazy machines in this day and age, but I would have _liked_ to think that you respected me enough to at least help bear your burden." He shook his head. "Hell, Steve, the things you must have gone through--"

"It wasn't so bad," he said honestly. "Most days I could forget. With a combination of lithium dioxide--"

"Swell. Wonderful. I'm glad you had it all worked out," he snapped.

Steve sighed, "Tony." He held out his hand.

Tony looked at him, and his shoulders slumped. "Sorry," he practically growled, clenching and unclenching his hands. "I'm not safe for you right now."

It would have sounded like a threat from any other man, but Steve knew better. When a twitch of his strength could break the arm of a chair, Tony didn't trust himself with his dying -- what, boyfriend? -- No, maybe not that anymore.

That had been part of the plan, too, to make it easier when Steve passed. But looking at Tony standing on the other side of the room, hunched and hurting, Steve realized he had been a fool.

"You won't hurt me," he said. "You've never hurt me." Then, firmer. "Tony come here."

Tony visibly wavered, but took a step forward, then another. Then, tentatively, every movement exquisitely gentle, he sat down on the side of the bed and wrapped strong arms around Steve, gathering him close in.

His exaggerated gentleness used to bother Steve; he made the mistake of assuming Tony thought him breakable. It wasn't until later he realized it was less about Steve being fragile and more that Tony didn't trust himself. Erskine's serum had made him inhumanly strong -- and Tony Stark had always been a man of passion, not self-control.

Now Steve leaned against Tony's broad chest, listened to his steady heartbeat, and tried not to think too much about how it hurt to breathe.

He felt Tony's eyes on the side of his neck, and although Steve didn't have a mirror he suspected he knew what was there. Without the lithium dioxide to mitigate the narcosis, his veins and capillaries would be darkening. Dying.

"How do I look?" he asked wryly.

"Seen worse," Tony said.

He wrinkled his nose. "You've been in the trenches."

"True," Tony held him, uncharacteristically quiet. One hand pressed over Steve's heart like he could keep it beating.

Steve closed his eyes and let himself drift for a moment or two, toying with sleep. But as always, his brain conjured up flash memories that startled him back into wakefulness. Ever since Afghanistan, he couldn't fall asleep unless he was exhausted. 

"I think I deserve this," Steve muttered, meaning his arc reactor, his inability to keep a healthy relationship, his... everything. "Peggy died right in front of me, in the convoy -- she died because of weapons I made. So many people, Tony..."

"I didn't know her. I was kinda napping at the time," Tony said, then added bluntly, "But I'm sure she would have been pretty sore at you for punishing yourself like this."

"Are you angry with me?" Steve asked.

Tony's hands tightened to almost a painful degree, then smoothed out as he caught himself. "Angrier with myself for not noticing," he murmured. One hand slowly dragged up and down Steve's sternum. Carefully, soothing.

Steve leaned back against him. He was tired, achy, and Tony's touch was familiar and reassuring. Steve _missed_ him, and he blamed that for his sudden, unguarded speech.

"I thought it would be easier to... back away. From us."  
  
"Easier for who?" Tony asked.

"You've lost so much," Steve answered. All Tony's friends, his world, his first love. He didn't want to be responsible for more.

Tony's voice took on an edge. "I'm _not_ losing you. Stark Junior says he has a cure, and since he's still walking around stirring up trouble, I'm inclined to believe him." He touched Steve's jaw, turning his head to the side to look him in the eye. "But he says it'll take some time. You need to hold out. Can you do that for me?"

In answer, Steve twisted upward to kiss him. A soft press of his lips against Tony's. He wasn't sure he had the right, but Tony didn't turn away.

Steve drew back, "As long as I'm able," he promised.

 


	4. Chapter 4

**Notes for the Chapter:**

> Thanks again DroolingFanGirl and CatChan for the help with the hand-wavy science behind the particle accelerator. 
> 
> Reminder that this is the last chapter from (mainly) Iron Tony's POV. The rest will be from Captain Stark, published in the second story in the series, Versa Vice.

 

Tony walked into Roger's hospital room, his mind half on the tablet of equations in front of him, half on the list of supplies he needed to requisition. He sort of expected Rogers to be asleep -- dying takes a lot out of a person -- he didn't expect him to be napping, half-propped up against Captain Stark's chest, both of them curled up on the too-small hospital bed.

Tony froze mid-step, causing Bucky to almost run into him with a tray full of Starbucks coffees.

"Watch it, Stark," the PA growled. Then, "Oh... finally."

Captain Stark opened his eyes at the noise and leveled what was probably his version of a Captain America Disapproving Glare, but was it ruined by the way his mouth kept twitching up on one side. Pleased.

And Tony couldn't take his eyes off the two of them.

Rogers came awake with a soft snort, then started coughing. Dry, shallow coughs that screwed up his face in pain. Stark gripped his shoulders, but Rogers shook his head, looking bloodless. "I'm," cough "fine." cough cough. He took a deep, shuttering breath, coughed into his fist again.

Stark didn't look happy, but glanced up to see Tony was still staring.

"See something you like?" Stark asked snidely.

"Not really," Tony lied. "Defacing the flag is a crime in my universe. Rogers here lives on the edge, but I am a stand-up citizen."

"Stark, your universe is strange." Bucky walked around him to hand a cup of steaming black coffee to the Captain. "You have a giant Steve running around, and I'm a one armed assassin."

" _What_?" Stark asked, looking oddly at Bucky.

Tony shrugged. "Long story." He glanced at Rogers, who seemed to have got his breath back. "They got you on lithium dioxide?"

Steve shook his head. "Taking me off it. Not approved for long term use." He gave a small smile, full of irony.

"Jesus, Steve," Bucky muttered.

Tony winced. "Been there, done it. Got the new arc reactor to prove it." He tapped his Vibranium reactor and came over to sit at the bedside chair -- which for some reason had a broken arm. "I took the fast and ugly way, instead of slow and agonizing. It made one hell of a last birthday party." He passed over the tablet. "You may want to look at this."

The speed which Rogers snatched it out of his hands and started flipping through schematics made Tony grin a little.

Stark made a move to get up, but Rogers touched his knee. Stark stilled, then settled back, one large hand encircling loose around Roger's waist. Another hitching feeling tightened Tony's chest -- it felt like, well maybe not full-on jealousy, but envy.

And a little like homesickness, too. 

Rogers lifted his hand, bringing the equations and blueprints from the screen to a holographic display. "A prismatic accelerator?" Rogers frowned, then glanced back to meet Tony's gaze. And Tony knew that _he knew_ how difficult the actual building of the accelerator would be. How close they were going to cut it.  This wasn't your garage-based particle reactor. The precision needed to be close to femtometer levels. 

Still holding his gaze, Roger's eyes flicked to the side, indicating Stark. Tony gave a slight nod.

Don't tell him. Got it.

"Bucky gave me access to Jocasta, but I'll probably need admin-level codes. You know, just in case she doesn't like me wielding enough power to irradiate an entire city block."

"Try not to. I like that block," Rogers said absently, pulling up a virtual calculator to check the balance of an equation. "But yes, you can have it."

"Speaking of access," Bucky said and the flat angry tone made Tony glance back out of well-developed self-preservation instincts. But the Winter Soldier always looked dead-eyed and remote. Bucky clearly seemed angry, his jaw set. "You gonna tell me how you managed to update your will without me knowing?"

Rogers blinked, then set the tablet aside. His chin lifting. "Natalie Rushman's still registered a legal council, even if she doesn't technically exist."

Bucky made a low, angry noise. "Change it back. You're not dying on our watch, and even if you were... I don't want any of it."

Tony and Stark exchanged a glance, not understanding.

"Bucky--"

"I'm a damn MBA. Do you know I'm in charge of _your_ retirement accounts right? I know what I'm doing with my paycheck, Steve. I'm set. I don't need your money."

Rogers took a breath that had an edge of a wheeze to it. The marks on his neck stood out. "You'd need it for upkeep."

"Upkeep of what?" Bucky snapped. "You'd planned to dissolve the company upon your death -- thanks for that heads-up, by the way."

Rogers set his jaw, then poked a few commands at the tablet. It asked for a password, which he muttered in an undertone. Then a schematic for an Iron Man armor appeared on the holoscreen.

Tony understood at once. He'd done the same with Rhodey, after all.

"Your suit?" Bucky asked, confused.

" _Your_ suit," Steve corrected. "Custom designed. I called it Project Rescue."

Bucky's eyes widened. He started to shake his head, then stopped.

"You've been bugging me for a suit," Steve said and coughed once. He passed over the tablet.

"I don't want it," Bucky said, stepping back. "Not like this, Steve. God damn you."

"Use it," Rogers insisted, his voice rough. " _I_   can't right now, and Jocasta is finalizing the fabrication."

Bucky looked at Captain Stark, who seemed surprised but set. He nodded once to Bucky. Then, oddly, Bucky turned to Tony, who shrugged.

"Just don't let the government rename it Iron Patriot."

Slowly, Bucky took the tablet, his eyes scanning over the blueprints for the suit for a long moment. He looked back to Steve. "This is only temporary. Just until you get back on your feet."

"I know."

"You jerk."

Steve smiled. "I know."

 

 

* * *

 

 

 

"Stark," the Captain said, catching Tony outside Steve's hospital room. "A word." 

It wasn't a request, and Tony wasn't sure if he was in the mood to deal with alternate-himself. Not when their timeline was so tight. "Make it snappy, Captain. I don't adjust my consulting fees for 1940's inflation."

"Good thing you're doing this for room and board, then," Stark said, leading him to a small conference room off to the side. He gestured Tony in and shut the door behind them. "Who did you give your armor to?" he asked bluntly. "When you were dying."

"I didn't. Rhodey took it. Well, borrowed it -- I sort of didn't lock his authorization out, and it was... I'd planned it somehow. It happened." He wiggled his hand back and forth in an 'eeeeh' gesture.

He didn't miss the look of grief that passed over Stark's face before he visibly willed it away. "How'd he do in it -- no, he always finished everything he set his mind to." He shook his head.

"Worried about Bucky?" Tony guessed.

"He's Steve's man-secretary. He's not a soldier."

An completely involuntary laugh strangled itself somewhere in Tony's throat. He didn't want to have this conversation, but the way his Steve had found out about Bucky was... terrible. If he could spare Stark that, all the better. "Look, Captain. There's something you should know about Rhodey..." And he went on to explain what had happened to his universe's Bucky Barnes, and what he had become.

Captain Stark's face was a mask, all except his eyes. His eyes looked every one of his twenty-something years. Too young to have to deal with the possibility of his best friend living a tortured life for seventy years.

When Tony finished, Stark gave a single nod, and Tony could almost see him push his grief down and to the side. The same way Steve would do when his emotions bubbled too close to the surface. It wasn't a Captain America thing -- it was how men in his generation were taught to deal.

"If that happens... if he's... well. We'll suss something out," Stark said, dragging his hand down his face. He still looked so young. "Thank you for the heads up."

"Hey, what are older, wiser alternate-universe counterparts for?" Tony said.

Stark let out a breath. "That may be. But going back... as much as I like Buck, he's a bean counter, not a Winter Soldier here." He fixed Tony with a look. "If the Avengers are called to assemble, you go up with him in your armor as support. We'll figure out something to say to the press, later."

"Tell them I'm in an automated suit," Tony suggested. "I can be Jocasta, or Jarvis. Whatever."

"And have the press flip their lids over 'Sky Net'?" Stark made finger quotes around the words, rolling his eyes.

"You watched the movies?" Tony was delighted. "I can't even get Steve to get past the first scene with the crushed skulls."

"Clint made me, and I didn't say I liked them."  He sighed and turned to the door. "It sounds like there's a lot of work you need to get done. Better get to it, Stark."

 

 

* * *

 

 

Rogers intern, Peter Parker, was a help. He was suspiciously bright, unrepentantly sarcastic, and although he wasn't Bruce (God, Tony missed Bruce. He missed _his_ Steve. He even sort of missed his Coulson -- this version here fawned too much on Captain Stark.)  Tony, liked the kid. Emphasis on _kid_. 

Parker had even had his own eureka moment, a few days later, while going through the suits data on the portal. He found a short, high frequency signal which appeared directly before the portal's opening and closing. It might be the alien version of an on/off switch.

They'd test it the next time the portal opened.

"Good work," Tony said, then not-so-casually tossed Parker an apple across the room. "Eat something. You're so skinny, you make me feel hungry."

His throw was off, but Parker still snatched the apple out of the air a second before it could bonk him on the head. "Thanks," he said, took a bite, and turned back to his computer station.

Tony smirked. Did Stark not expect him to figure out who the kid was?  

Though that was easily the highlight of the next few days. 

Rogers was fading. Despite all the doctors had him on, he was dying, and Bucky and Tony worked as hard as they can, going without sleep, begging, bribing for materials that, technically, civilians shouldn't have. Once or twice, Bucky flew his new armor out to fetch parts when delivery was too slow (and though Bucky wouldn't admit it, Tony suspected some of what they'd managed to cobble together had been from someone's black market).

Tony even caved and asked for a few things from Coulson's Shield resources. He pretended not to notice the man was taking notes. If Shield mooks replicated the artificial vibranium reactor process... well, he'd been desperate.

But it wasn't enough. Rogers, now hooked to an oxygen mask 24/7 nodded, when Tony came into his room to visit with the newest specs. Rogers took the tablet with a grimace, like it weighed a hundred pounds. The skin under Roger's fingernails had taken on a blue tinge.

Rogers didn't say anything, but glanced up from the tablet to Tony once or twice with a resigned look, and Tony _knew_ that he knew.

The work wasn't going fast enough.

And damn Rogers for being so quiet and brave about it. When Tony thought of Monaco, of his birthday party, and the quiet dignity Rogers showed here, he felt a swell of shame.

"It'll happen," Tony said, grabbing the tablet back. "We'll make it happen."

Rogers shook his head. "This is the no bullshit zone, Stark."

"Really? Did you just curse at me? Rogers, I'm shocked. _Shocked_."

"Give me a break, I'm dying." Rogers cocked his head at Tony. "I really don't curse, in your universe?"

"I heard him say 'rats'. Once."

Roger's lips twisted into a pale grin. "My mom used to actually wash my mouth out with vinegar when I slipped up around her as a kid. I wonder if--" he chuckled, but it turned into a hard, wracking cough. Grimacing, Rogers removed the oxygen mask long enough to spit red into a cup.

Tony winced. But before he could say something -- or joke, to be honest, the only thing he could do in these kinds of situations was joke -- Captain Stark knocked and opened the door, tucking an Avengers communicator into his pocket.

"Okay boys, we have a portal opening in New Brunswick."

Rogers struggled to rise, breathing harshly into his oxygen mask. "Another one? Now? It's too early," he wheezed. He and Tony exchanged a look.

"Doesn't matter," Tony said, standing. A tingle of excitement went down his spine.. He wasn't about to look a gift horse in the mouth. "We can still send someone through, then send the signal Parker found to shut it off after they're done."

"Stop the invasion," Rogers agreed. "And if we can turn it off, we know we have the key. The same signal should--should flip," he coughed, "the portal back on. Trace them back to their source."

Stark's head swiveled back and forth between them like he was watching a ping-pong match. "Slow down, brains. What are you two talking about?"

"I have spare reactors inside the tower," Tony said. "The Avengers tower in my universe. I'll get it and come back. We fix your boyfriend, no new particle accelerator needed."

"No," Stark said. There was a tone that made Tony stiffen his spine -- not out of defense, but out of natural authority. "You'll stay here. You're still the best shot to build the accelerator in case something goes wrong. You stay. I'll go."

Rogers shook his head, reaching out a thin hand to grip Stark's wrist. "We don't know if going back through the portal will lead to his universe, or another."

"All the more reason he should stay," Stark said.

Something in Tony balked at that. Home was just a portal-trip away, and a large (probably cowardly) part of him wanted to flee. He didn't want to face this dying Steve Rogers... he wanted to see his Steve, whole and healthy.

But even though Tony knew he was a selfish ass, it didn't mean he had to act on it. He hadn't been that man since Afghanistan. Besides, if this worked... "Yeah. Fine. Give me fifteen minutes, I'll get you the passcodes to the lab. You can have fun explaining everything to my team."

For the first time in days, a sly smile tugged at Stark's lips. "I can be very persuasive."

"Tony," Rogers tried to sit up. "There's a lot of risk involved. You can't," cough "you shouldn't-- for me."

"Shut your trap, Steve," Stark said fondly. Then he leaned down and cupped Roger's cheek, drew down his oxygen mask, and kissed him. Rogers made a low sound and kissed him back, his fingers tangling with Stark's -- the blue tinged nails garish against the Captain's healthy skin. 

Tony again felt a weird sort of jealousy for his other self, even though this wasn't his Steve and...

Tony made himself turn away.

Fifteen minutes. There was a lot he could do in fifteen minutes.

 

* * *

 

Captain Stark

 

* * *

 

At supersonic speeds, it didn't take the jet long to reach New Brunswick, PA.

"Shield agents put the portal about thirty feet up in the air, directly ahead," Natasha said from the pilot's seat.

Tony gave a nod. It figured whoever was sending the aliens over wouldn't want their portal destroyed, like last time.

There were three of the big, ugly rock-like aliens causing havoc and destruction. A swarm of bat-aliens screeched and flowed in groups around their feet. He didn't want to think about how many people had already been caught up in the mess.

Tony wanted to knock heads, wanted to make these guys _pay_ , but it wasn't in the cards this time around.

Stark had come along, as requested. Tony still wasn't used to seeing himself in an Iron Man armor, even if it was a bulkier, more heavy-duty design than Steve's. 

Steeling himself, he nodded to his counterpart and stood by him for a word.

"Give me five minutes to get through the portal, then activate that frequency you and Steve were talking 'bout. Shut it down." He grinned at Stark's expression, though he felt more sick than happy. "What, you thought I wasn't following along with your conversation?"

The look on Stark's face clearly said he hadn't. "Bad idea, Captain. We don't know for certain the portal goes back to my world, or if the frequency reopens it again."

This was the part Tony had been dreading. He knew that, and he felt torn apart by it. But it wasn't the first time he'd trusted his life to a science he barely understood. "The longer that portal's open, the more people die." He nodded out to the rampaging aliens. "It shuts down, they freeze in place again."

And come hell or high water, he was going to find a way to reopen the portal from the other side -- no matter what universe it dumped him in. If there was a vibranium reactor over there, he was coming back with it.

Besides, he held a trump card of his own.

He could see Stark wanted to object, but there was the logic in his argument. Stark nodded.

Tony gripped his red and gold metal arm, giving it enough of a squeeze to ensure Stark felt it. "If I don't come back -- you gotta finish the accelerator. You understand?"

"Gee, really? Thanks, Cap." But Stark handed him over a USB stick. "This has the codes you need as well as the frequency. Find Dr. Banner and give it to him. You'll need this, too." He gave Tony a communicator. "It's set to the frequencies my team uses." He hesitated. "Good luck."

"Don't need luck," Tony answered, with bravado he didn't feel.

Stark smirked. Then the visor of his Iron Man suit clicked shut over his face. He flew out the hatch of the jet.

Tony turned to Bucky, who was clad in his own suit. It was Steve's design -- the metal plates thinner, but vastly more maneuverable. The armor itself was of a different color scheme; cloudy dark purple, with silver chrome highlights.

"You wanna give me a lift?" Tony asked.

Bucky looked sick to his stomach, but he nodded gamely enough. Rescue's metal visor flowed over his face -- Steve's design again -- and when he lifted Tony up, his flight was smooth.

They came to the shimmering circle in the sky a few moments later.

"Good luck!" Rescue yelled, and shoved him through the portal.

Tony braced himself for, well, anything really. He'd caught a movie called Stargate and thought the journey might be a little like that. But Bucky shoved him, and then suddenly he was falling. No change at all.

 _It didn't work,_ he thought, but landed on the ground in a crouch, the point of his shield down. Damn it all, something had gone wrong. It hadn't worked.

He glanced up, scanning for Bucky. They would just have to try again. But the sky was empty. Well, except for a giant rock alien who seemed to be taking out his aggression on a nearby building.

Tony had no time to consider before something smacked hard into him from behind, staggering him a step forward. He had one moment to put an arm up to block a sparking widow's bite to the neck. Strong, lithe legs encircled his shoulders -- Natasha always flowed more than fought.

But Tony had his tangles with her -- or a version of her -- in late night sparring sessions when both couldn't sleep. He didn't use the shield, he didn't want to hurt her. Instead, he dropped down into a crouch, then flat back. She caught the edge of his cowl to hold on, and it came away in her hands as she rolled away to safety.

Immediately, she was on her feet again. Her face was stone, but her eyes were very wide.

Tony stood, letting her look her fill. "Let me guess," he drawled and took a gander at this world which really wasn't _his_ world after all, "Steve's Captain America here."

Her silence was as good as a yes, and Tony internally pumped his fist in victory, though his day was about to get really, really strange.

"Who are you?" she asked, flat and dangerous.

"Really, Nat? This get-up doesn't tip you off?"

"I saw you come through the alien portal."

He shrugged. "They're attacking my dimension, too." He smiled, all teeth. "I figured it's about time we used their knowledge against them."

Suddenly the second communicator in his ear -- the one Tony had given him, crackled to life.

"Holy crap," said Clint's startled voice. "Nat, who is that? Is that... Tony?"

"Tony?" Repeated Rogers -- Holy mother, he sounded just like his Steve. "He's here? He's okay?"

Natasha visibly hesitated before answering. So Tony decided to cut in. "I'm not your Tony," he said.

"You can say that again," Clint added.

Tony squinted around the skyline until he saw Clint's silhouette, probably picking off aliens from up high. Tony gave a sarcastic wave. "You're a doll in any universe, Barton. But your Stark is fine. He's been camping out in my universe--"

He stopped as sudden silence fell over the city. The rock aliens froze in place, the screaming bats went quiet and still. Lifeless. Tony knew without looking the portal had shut off. Stark had done his job, now it was time for Tony to do his.

Natasha, to her credit, didn't look thrown at all.  "How do we know he's not a prisoner?"

Tony lifted his eyebrows. "You think it's possible to keep any Iron Man where he doesn't want to be? He's working with our scientists." Saving Steve's life, he didn't add because Nat wasn't the type to be swayed by pity.

"We need proof of life," Natasha said.

"You can have it," Tony said, purposefully keeping his free hand away from his pocket where he had tucked the USB. "In fact, you're more than welcome to come get him." He gestured to where the portal had just been a few moments before, and glanced back at this strange version of Natasha. "We just shut down the portal on our side -- which stops the aliens cold. I have the key to reopen it, and its all yours soon as I get my hands on one of your Stark's vibranium arc reactors."

Natasha's eyes narrowed.

Roger's voice cut through the comm lines, cold and angry. "That sounds like a threat, Stark."

"Not a threat, just an exchange. Big difference."

Rogers was silent over the comm lines for a moment, and Tony could practically hear his teeth grind. "Widow, I'm by the town hall on main street. Bring him here."

Yup. Rogers was pissed, but Tony Stark knew how to play hard ball even before he became Captain America. And when it came to Steve's life, he was taking no chances. Not when the Tony Stark of this universe had already kept information back from him, and hell, maybe they were cut from the same cloth. Tony didn't care.

Squaring his shoulders, he indicated Natasha to lead on.

 

 


End file.
